Performic acid on-site generator and formulator

ABSTRACT

Methods of generating performic acid by contacting aqueous oxidizing agent and aqueous formic acid source in liquid phase are disclosed. A system and apparatus for the in situ production of the performic acid chemistries is further disclosed. In particular, a continuous flow reactor is provided to generate performic acid at variable rates. Methods of employing the oxidizing biocide for various disinfection applications are also disclosed.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 62/214,340 filed on Sep. 4, 2015 and U.S. Provisional ApplicationSer. No. 62/303,746 filed on Mar. 4, 2016 each entitled “Performic AcidOn-Site Generator and Formulator,” the entire disclosure of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to methods of on-site generation ofperformic acid using a generator or formulated system. The formation ofperformic acid is achieved on-site by contacting an aqueous oxidizingagent and aqueous formic acid in liquid phase under heated laminar orturbulent flow conditions. In particular, a continuous flow reactor isprovided to generate performic acid at variable rates, including nearinstantaneous generation. The on-site generated performic acid and/ormixed peracid composition is suitable for providing an oxidizing biocidefor various disinfection applications. The generated performic acidcompositions are useful for treating a target, e.g., surface(s) and/orother items used in papermaking, textiles, food, or pharmaceuticalindustry, target water and/or treating a biofilm.

BACKGROUND OF THE INVENTION

Performic acid (or peroxyformic acid) is considered an industriallyimportant percarboxylic acid. Performic acid has an advantageous degreeand range of microbiocidal properties compared to other peroxycarboxylicacids, such as peracetic and perproprionic acids, as disclosed by V.Merka et al in J. Hyg. Epidem. Microbiol. Immunol, 1965 (IX) 220, aswell as in European Patent Application No. 863,098,96.

Peroxycarboxylic acid compositions are generally made through an acidcatalyzed equilibrium reaction. Most often, the peroxycarboxylic acidsare generated in a chemical plant, and then shipped to customers foron-site use. Due to the limited storage stability of peroxycarboxylicacids, the peroxycarboxylic acids must be packed in special containersand shipped under strict Department of Transportation (DOT) guidelines.Further, excess amounts of reagents (e.g., acids, oxidizing agents, andstabilizers) are present in the compositions during shipping to preventdecomposition. For peroxyformic acid, however, the inherent instabilityof the substance relative to the higher alkyl peracid, and the explosivenature of the substance at the concentrate make it an even moresignificant challenge to be manufactured, stored and transported beforedilution prior to use, in the similar way like higher alkyl peracid.Thus, there are needs for the on-site generation of peroxycarboxylicacids, especially peroxyformic acid.

Performic acid is formed by part of the original reagents and reactionproducts form an equilibrium mixture. However, such a mixture may berather unstable and/or reactive in handling and in storage, typicallyhaving a relative short shelf life. The stability of performic acid, incomparison to other peroxycarboxylic acids such as peracetic acid,presents stability challenges from 1-2 orders greater. For example, thehalf-life of performic acid is in the order of minutes to hours,compared to the half-life of peracetic acid which is weeks to months.Due to the characteristics of performic acid in having significantlylower shelf life stability there remains a need to provide in situgeneration for use on-site without requiring storage and/or shipment.

Performic acid is extremely useful and effective in various field oftechnology such as disinfection, in spite of its instability. Formedfrom the reaction of hydrogen peroxide and formic acid, it reacts morerapidly and powerfully than peracetic acid before breaking down to waterand carbon dioxide. Performic acid is an environmentally friendlyoxidizing biocide for various disinfection applications. The applicationareas involve microbial growth control and cleaning of surfaces inlarger industrial scale such as municipal or industrial waste waterpurification, or for circulation of process waters in pulp and paperindustry. These compositions are most applicable for example inhospitals, dental surgeries, kitchens, and bathrooms to kill infectiousorganisms.

Performic acid solutions are highly reactive. If performic acidsolutions are contacted with impurities such as zinc dust, lead dioxide,or sodium azide they may react violently and decompose. Performic acidtypically decomposes as such into carbon dioxide and water within a fewhours at ambient temperature and pressure.

Typically, performic acid is formed by reacting aqueous formic acid withaqueous hydrogen peroxide through an exothermic reaction in the presentof a strong mineral acid catalyst, such as sulfuric acid. Due to itsinstability, performic acid solutions should be prepared in situpreferably at the point of use or directly before use depending on theproperties of the reactants and reaction points. However, the presenceof strong mineral acid, such as sulfuric acid, in pipes can lead tocorrosion of the material and contamination of the process stream.

Accordingly, it is an objective of the invention to provide a method forgenerating performic acid in situ without the presence of an acidcatalyst, such as a strong mineral acid catalyst.

A further objective of the invention includes providing a method forgenerating performic acid in situ employing with heat as the onlycatalyst, without additional chelating and/or stabilizing agents.

A still further objective of the invention is to provide on-sitegenerator apparatus for a continuous flow reaction with variable ratesof generating performic acid.

Additional objectives of the invention include generating the performicacid as well as mixed peracid compositions including performic acid insitu. Other objects, advantages and features of the present inventionwill become apparent from the following specification taken inconjunction with the accompanying drawings.

BRIEF SUMMARY OF THE INVENTION

In an embodiment, the present invention provides an adjustable biocideformulator or generator system for on-site performic acid formingcomposition generation. The formulator or generator system comprises atleast one inlet, a length of pipe, a heating device, and an outlet fordosing a performic acid forming composition. In an aspect, the inlet(s)are in fluid connection with the length of pipe and supply reagents toproduce performic acid in the length of pipe. In a further aspect, thereagents comprise a formic acid source and an oxidizing agent. In afurther aspect, the length of pipe is in fluid connection with theoutlet to dispense the performic acid forming composition.

In an embodiment, the present invention provides a method of on-sitegenerating performic acid forming composition comprising: providing aformic acid source to a length of pipe at a desired flow rate; providingan oxidizing agent to said length of pipe at a desired flow rate;contacting said formic acid source with an effective amount of saidoxidizing agent within said length of pipe in the presence of a heatingdevice to form a performic acid; delivering said performic acid to adownstream process. In a further aspect, the method includes a heatingdevice that provides sufficient heat to raise the temperature of thesolution within the length of a pipe to a temperature not exceeding 180°C. and wherein said heating device is a cartridge (for example)contained with said length of pipe and wherein the difference betweensaid pipe's inner diameter and said cartridge's diameter is less thanabout 5 inches. In a further aspect, the method includes cooling saidperformic acid to a temperature at or below freezing. In a still furtheraspect, the method includes measuring variables including conductivity,temperature, product levels, concentrations, IR/UV/VIS spectroscopy,pressure, performic acid and/or oxidant concentrations, and/or flow rateand controlling the method using control software for operating saidapparatus to generate a user- or system-inputted performic acid formingcomposition and said desired flow rate of said performic acid formingcomposition for on-site generation. In a further aspect, the presentinvention includes a performic acid compositions formed using the methodof the invention.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description, which shows and describesillustrative embodiments of the invention. Accordingly, the drawings anddetailed description are to be regarded as illustrative in nature andnot restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of a user or controller operatedadjustable biocide formulator apparatus according to an embodiment ofthe invention.

FIG. 2 shows diagram an exemplary embodiment of an adjustable biocideformulator apparatus according to the invention.

FIG. 3 shows diagram an exemplary embodiment of an adjustable biocideformulator apparatus according to the invention.

FIG. 4 shows diagram an exemplary embodiment of an adjustable biocideformulator apparatus according to the invention.

FIG. 5 shows modeling of fluid flow through the reactor according to anembodiment of the invention, indicating a correlation between flowrates, tubing diameter, and temperature of the cartridge

FIG. 6 shows the relationship between fluid bulk temperature cartridgeheater skin temperature and flow rate according to an embodiment of theinvention.

FIG. 7 shows the effect of reagent inlet temperature and heater poweraccording to an embodiment of the invention.

FIG. 8 shows conductivity measured from two independent experimentsdesigned to generate performic acid by mixing of formic acid andhydrogen peroxide according to an embodiment of the invention.

FIG. 9 shows a diagram of an exemplary embodiment of an adjustablebiocide formulator apparatus according to the invention employing adownward flow of oxidizing agent for the generation of performic acid.

FIG. 10 shows a diagram of an exemplary embodiment of an adjustablebiocide formulator apparatus according to the invention employing adownward flow of mixed reagents for the generation of performic acid.

FIG. 11 shows experimental results demonstrating iodometric titration ofperformic acid generated by an adjustable biocide formulator apparatusaccording to an embodiment of the invention.

FIG. 12 shows a diagram of an exemplary embodiment of an adjustablebiocide formulator apparatus according to the invention.

FIG. 13 shows experimental results demonstrating microbial efficacy ofPFA generated according to an exemplary embodiment of the invention.

FIG. 14 shows experimental results demonstrating PFA oxidizing FeS intoiron oxide according to an exemplary embodiment of the invention.

Various embodiments of the present invention will be described in detailwith reference to the drawings, wherein like reference numeralsrepresent like parts throughout the several views. Reference to variousembodiments does not limit the scope of the invention. Figuresrepresented herein are not limitations to the various embodimentsaccording to the invention and are presented for exemplary illustrationof the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure relates to performic acid formulator or generatorsystems for on-site performic acid generation, including mixed peracidcompositions comprising performic acid, as well as methods of making andusing such compositions. The compositions and systems for making thecompositions disclosed herein have many advantages over conventionalsystems and methods for making performic acid compositions. For example,the system allow on-site, user-or system-controlled formulation,eliminating the step of storing unstable performic acid compositions. Inaddition, there are various advantages of the compositions, includinghaving significantly lower reactant inputs, increased stability, andability to be generated in situ or on site.

The embodiments of this invention are not limited to particular methodsand systems for on-site generation of performic acid, which vary and areunderstood by skilled artisans. It is further to be understood that allterminology used herein is for the purpose of describing particularembodiments only, and is not intended to be limiting in any manner orscope. For example, as used in this specification and the appendedclaims, the singular forms “a,” “an” and “the” can include pluralreferences unless the context clearly indicates otherwise. Further, allunits, prefixes, and symbols may be denoted in their SI accepted form.Numeric ranges recited within the specification are inclusive of thenumbers defining the range and include each integer within the definedrange.

So that the present invention may be more readily understood, certainterms are first defined. Unless defined otherwise, all technical andscientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which embodiments ofthe invention pertain. Many methods and materials similar, modified, orequivalent to those described herein can be used in the practice of theembodiments of the present invention without undue experimentation; thepreferred materials and methods are described herein. In describing andclaiming the embodiments of the present invention, the headings providedare not limitations on the embodiments of the invention and thefollowing terminology will be used in accordance with the definitionsset out below.

The term “about,” as used herein, refers to variation in the numericalquantity that can occur, for example, through typical measuring andliquid handling procedures used for making concentrates or use solutionsin the real world; through inadvertent error in these procedures;through differences in the manufacture, source, or purity of theingredients used to make the compositions or carry out the methods; andthe like. The term “about” also encompasses amounts that differ due todifferent equilibrium conditions for a composition resulting from aparticular initial mixture. Whether or not modified by the term “about”,the claims include equivalents to the quantities.

The term “cleaning,” as used herein, means to perform or aid in soilremoval, bleaching, microbial population reduction, or combinationthereof.

As used herein, the term “disinfectant” refers to an agent that killsall vegetative cells including most recognized pathogenicmicroorganisms, using the procedure described in A.O.A.C. Use DilutionMethods, Official Methods of Analysis of the Association of OfficialAnalytical Chemists, paragraph 955.14 and applicable sections, 15thEdition, 1990 (EPA Guideline 91-2). As used herein, the term “high leveldisinfection” or “high level disinfectant” refers to a compound orcomposition that kills substantially all organisms, except high levelsof bacterial spores, and is effected with a chemical germicide clearedfor marketing as a sterilant by the Food and Drug Administration. Asused herein, the term “intermediate-level disinfection” or “intermediatelevel disinfectant” refers to a compound or composition that killsmycobacteria, most viruses, and bacteria with a chemical germicideregistered as a tuberculocide by the Environmental Protection Agency(EPA). As used herein, the term “low-level disinfection” or “low leveldisinfectant” refers to a compound or composition that kills someviruses and bacteria with a chemical germicide registered as a hospitaldisinfectant by the EPA.

As used herein, the phrase “food processing surface” refers to a surfaceof a tool, a machine, equipment, a structure, a building, or the likethat is employed as part of a food processing, preparation, or storageactivity. Examples of food processing surfaces include surfaces of foodprocessing or preparation equipment (e.g., slicing, canning, ortransport equipment, including flumes), of food processing wares (e.g.,utensils, dishware, wash ware, and bar glasses), and of floors, walls,or fixtures of structures in which food processing occurs. Foodprocessing surfaces are found and employed in food anti-spoilage aircirculation systems, aseptic packaging sanitizing, food refrigerationand cooler cleaners and sanitizers, ware washing sanitizing, blanchercleaning and sanitizing, food packaging materials, cutting boardadditives, third-sink sanitizing, beverage chillers and warmers, meatchilling or scalding waters, autodish sanitizers, sanitizing gels,cooling towers, food processing antimicrobial garment sprays, andnon-to-low-aqueous food preparation lubricants, oils, and rinseadditives.

As used herein, the phrase “food product” includes any food substancethat might require treatment with an antimicrobial agent or compositionand that is edible with or without further preparation. Food productsinclude meat (e.g., red meat and pork), seafood, poultry, produce (e.g.,fruits and vegetables), eggs, living eggs, egg products, ready to eatfood, wheat, seeds, roots, tubers, leafs, stems, corns, flowers,sprouts, seasonings, or a combination thereof. The term “produce” refersto food products such as fruits and vegetables and plants orplant-derived materials that are typically sold uncooked and, often,unpackaged, and that can sometimes be eaten raw.

As used herein, the term “fouling” shall be understood to mean theundesirable presence of or any deposition of any organic or inorganicmaterial in the applicable composition or chemistry.

As used herein, the term “free” or “substantially free” refers to acomposition, mixture, or ingredient that does not contain a particularcompound or to which a particular compound or a particularcompound-containing compound has not been added. Should the particularcompound be present through contamination and/or use in a minimal amountof a composition, mixture, or ingredients, the amount of the compoundshall be less than about 3 wt-%. More preferably, the amount of thecompound is less than 2 wt-%, less than 1 wt-%, and most preferably theamount of the compound is less than 0.5 wt-%.

As used herein, the term “microorganism” refers to any non-cellular orunicellular (including colonial) organism. Microorganisms include allprokaryotes. Microorganisms include bacteria (including cyanobacteria),spores, lichens, fungi, protozoa, virinos, viroids, viruses, phages, andsome algae. As used herein, the term “microbe” is synonymous withmicroorganism.

As used herein, the terms “mixed” or “mixture” when used relating to“performic acids” or “performic acid composition” refer to a compositionor mixture including performic acid and at least one otherperoxycarboxylic acid.

As used herein, the terms “performic acid” or “peroxyformic acid” referto an acid having the formula of CH₂O₃ and the structure:

In general, performic acid is generated by combining formic acid andhydrogen peroxide under acidic conditions to yield performic acid andwater (as shown) and one skilled in the art will ascertain thatadditional carboxylic acids and percarboxylic acids could further beincluded in the generation steps according to the present invention.

HCOOH+H₂O₂

HCO₂OH+H₂O

As used herein, the term “sanitizer” refers to an agent that reduces thenumber of bacterial contaminants to safe levels as judged by publichealth requirements. In an embodiment, sanitizers for use in thisinvention will provide at least a 99.999% reduction (5-log orderreduction). These reductions can be evaluated using a procedure set outin Germicidal and Detergent Sanitizing Action of Disinfectants, OfficialMethods of Analysis of the Association of Official Analytical Chemists,paragraph 960.09 and applicable sections, 15th Edition, 1990 (EPAGuideline 91-2). According to this reference a sanitizer should providea 99.999% reduction (5-log order reduction) within 30 seconds at roomtemperature, 25+/−2° C., against several test organisms.

For the purpose of this patent application, successful microbialreduction is achieved when the microbial populations are reduced by atleast about 50%, or by significantly more than is achieved by a washwith water. Larger reductions in microbial population provide greaterlevels of protection.

Differentiation of antimicrobial “-cidal” or “-static” activity, thedefinitions which describe the degree of efficacy, and the officiallaboratory protocols for measuring this efficacy are considerations forunderstanding the relevance of antimicrobial agents and compositions.Antimicrobial compositions can affect two kinds of microbial celldamage. The first is a lethal, irreversible action resulting in completemicrobial cell destruction or incapacitation. The second type of celldamage is reversible, such that if the organism is rendered free of theagent, it can again multiply. The former is termed microbiocidal and thelater, microbistatic. A sanitizer and a disinfectant are, by definition,agents which provide antimicrobial or microbiocidal activity. Incontrast, a preservative is generally described as an inhibitor ormicrobistatic composition.

As used herein, the term “ware” refers to items such as eating andcooking utensils, dishes, and other hard surfaces such as showers,sinks, toilets, bathtubs, countertops, windows, mirrors, transportationvehicles, and floors. As used herein, the term “warewashing” refers towashing, cleaning, or rinsing ware. Ware also refers to items made ofplastic. Types of plastics that can be cleaned with the compositionsaccording to the invention include but are not limited to, those thatinclude polycarbonate polymers (PC), acrylonitrile-butadiene-styrenepolymers (ABS), and polysulfone polymers (PS). Another exemplary plasticthat can be cleaned using the compounds and compositions of theinvention include polyethylene terephthalate (PET).

The term “weight percent,” “wt-%,” “percent by weight,” “% by weight,”and variations thereof, as used herein, refer to the concentration of asubstance as the weight of that substance divided by the total weight ofthe composition and multiplied by 100. It is understood that, as usedhere, “percent,” “%,” and the like are intended to be synonymous with“weight percent,” “wt-%,” etc.

EMBODIMENTS OF THE INVENTION Performic Acid Chemistries

According to an embodiment of the invention methods and apparatus foron-site generation of performic acid chemistries for use as cleaningagents including for example, antimicrobial applications, bleachingapplications, and other cleaning and anti-scaling applications. Themethods and apparatus according to the invention are capable of on-sitegeneration of performic acid chemistries according touser-specifications. As referred to herein, performic acid chemistriesare further understood to include mixed performic acid chemistries. Theinvention overcomes the shortfalls of commercial-available performicacid by providing user-specific formulations with enhanced performanceefficacy. In addition, the methods and apparatus use heat as thereaction catalyst, beneficially reducing the costs and hazardsassociated with transporting active chemistries, providing activechemistries with increased shelf-lives and reduction of waste of activechemistries as a result of on-site user-identified performic acidproduction according to the invention.

The methods and apparatus of the present invention overcome significantlimitations of conventional methods of performic acid generation,typically acid catalyzed equilibrium reactions. The methods andapparatus of the present invention overcome the many downsides to suchconventional methods, including, but not limited to elimination of theuse of excess amounts of reactants, and hazardous shipping conditions.

While an understanding of the mechanism is not necessary to practice thepresent invention and while the present invention is not limited to anyparticular mechanism of action, it is contemplated that, in someembodiments the benefits afforded according to the invention result fromthe use of heat as the sole catalyst in the methods and apparatus of thepresent invention for generating on site performic acid. Beneficially,the reacted performic acids according to the invention are obtained ingreater amounts than in equilibrium chemistry wherein greater amounts ofoxidizing agent, e.g. hydrogen peroxide, and other reagents would bepresent. According to the present invention, an aqueous solution of theperformic acid(s) produced contains a relatively higher concentration ofperformic acid(s) compared to unreacted oxidizing agent, e.g. hydrogenperoxide component. Preferably, the average performic acid concentrationis at least 1 wt-%, at least 2 wt-%, at least 3 wt-%, at least 4 wt-%,at least 5 wt-%, at least 6 wt-%, at least 7 wt-%, at least 8 wt-%, atleast 9 wt-%, at least 10 wt-%, at least 11 wt-%, at least 12 wt-%, atleast 13 wt-%, at least 14 wt-%, or at least 15 wt-%. More preferably,the average performic acid concentration is at least 2 wt-%, and morepreferably the average performic acid concentration is at least 5.5wt-%. This is significantly advantageous for the antimicrobial and othercleaning applications disclosed herein as desirable according to theembodiments of the invention. However, as one skilled in the art willappreciate, the average performic acid concentration will vary dependingon heating, flow rate, temperatures, pressures, concentration of thereagents, etc.

Rather than providing a performic acid composition in an equilibriummixture, in situ generation of the performic acid composition allows theperformic acid to be produced stoichiometrically through selecting thecomposition of the starting materials. The in situ systems of thepresent invention therefore generate higher concentrations of theperformic acids than are available in equilibrium systems. Inparticular, according to the invention the systems generate higherconcentrations of the performic acid and lower concentrations ofhydrogen peroxide (e.g. unreacted reagents) than achieved in equilibriumsystems. Preferably, the average performic acid concentration is atleast 1 wt-%. More preferably, the average performic acid concentrationis at least 5 wt-%, and more preferably the average performic acidconcentration is at least 5.5 wt-%. Preferably, the average hydrogenperoxide concentration is less than 10 wt-%. More preferably, theaverage hydrogen peroxide concentration is less than 5 wt-% and morepreferably, the average hydrogen peroxide concentration is less than 1wt-%. However, as one skilled in the art will appreciate, the averageconcentration of performic acid and/or hydrogen peroxide will varydepending on heating, flow rate, temperatures, pressures, concentrationof the reagents, etc.

In some aspects, the methods of the present invention generate performicacid(s) without the need for additional chelating and/or stabilizingagents, although such agents are compatible with these systems they arenot required components. Instead, chelating and/or stabilizing agentsare suitable additional functional ingredients which may be included inthe methods of generating the performic acid and/or added aftercompletion of the reaction forming the performic acid compositions priorto use, and/or during generating a use solution of the performic acidcompositions.

In some aspects, the present invention requires acidic conditions.Preferably, in some embodiments, the pH of the system does not exceed 7.More preferably, the pH does not exceed 5. More preferably, the pH doesnot exceed 3. Still more preferably, the pH does not exceed 2.

Beneficially, the performic acid compositions generated according to theinvention may be further combined or produced in combination withadditional chemistries, such as for example equilibrium chemistries,such as additional peroxycarboxylic acid compositions.

Eliminated Functional Ingredients

Unlike conventional equilibrium based performic acid compositions, thecompositions disclosed herein are formed from a non-equilibriumreaction. Further, the composition disclosed herein can be usedimmediately after generation. Thus, many of the additional ingredientsrequired in equilibrium based compositions do not need to be included inthe present compositions. In some embodiments stabilizing agents arepreferred for certain compositions according to the invention andprovide benefits. However, beneficially, the use of non-equilibriumchemistry according to the present invention optionally provides thatthe compositions can be free of, or substantially free of a stabilizingagent.

Stabilizing agents are commonly added to equilibrium performic acidcompositions to stabilize the performic acid and hydrogen peroxide andprevent the decomposition of these constituents within the compositions.Various embodiments of the invention do not require the use of at leastone or more of such stabilizing agents. Examples of stabilizing agentsmay include for example, surfactants, couplers, hydrotropes, acidcatalysts and the like that are conventionally used in equilibriumperformic acid compositions to stabilize and improve shelf life of thecomposition.

Further examples of stabilizing agents include, for example, chelatingagents or sequestrants. Such sequestrants include, but are not limitedto, organic chelating compounds that sequester metal ions in solution,particularly transition metal ions. Such sequestrants include organicamino- or hydroxy-polyphosphonic acid complexing agents (either in acidor soluble salt forms), carboxylic acids (e.g., polymericpolycarboxylate), hydroxycarboxylic acids, aminocarboxylic acids, orheterocyclic carboxylic acids, e.g., pyridine-2,6-dicarboxylic acid(dipicolinic acid). Dipicolinic acid, 1-hydroxyethylidene-1,1-diphosphonic acid (CH3C(PO3H2)2OH) (HEDP) are furtherexample of stabilizing agents.

Additional examples of stabilizing agents commonly used in equilibriumchemistry to stabilize the performic acid and hydrogen peroxide and/orprevent the premature oxidation of the composition include phosphonicacid or phosphonate salt. Phosphonic acids and phosphonate salts includeHEDP; ethylenediamine tetrakis methylenephosphonic acid (EDTMP);diethylenetriamine pentakis methylenephosphonic acid (DTPMP);cyclohexane-1,2-tetramethylene phosphonic acid; amino[tri(methylenephosphonic acid)]; (ethylene diamine[tetra methylene-phosphonic acid)];2-phosphene butane-1,2,4-tricarboxylic acid; or salts thereof, such asthe alkali metal salts, ammonium salts, or alkyloyl amine salts, such asmono, di, or tetra-ethanolamine salts; picolinic, dipicolinic acid ormixtures thereof. In some embodiments, organic phosphonates, e.g., HEDPare well known as used stabilizing agents.

Exemplary commercially available food additive chelating agents includephosphonates sold under the trade name DEQUEST® including, for example,1-hydroxyethylidene-1,1-diphosphonic acid, available from MonsantoIndustrial Chemicals Co., St. Louis, Mo., as DEQUEST® 2010;amino(tri(methylenephosphonic acid)), (N[CH₂PO₃H₂]₃), available fromMonsanto as DEQUEST® 2000; ethylenediamine[tetra(methylenephosphonicacid)] available from Monsanto as DEQUEST® 2041; and2-phosphonobutane-1,2,4-tricarboxylic acid available from Mobay ChemicalCorporation, Inorganic Chemicals Division, Pittsburgh, Pa., as BayhibitAM. Further exemplary sequestrant can be or include aminocarboxylic acidtype sequestrant. Suitable aminocarboxylic acid type sequestrantsinclude the acids or alkali metal salts thereof, e.g., amino acetatesand salts thereof. Suitable aminocarboxylates includeN-hydroxyethylaminodiacetic acid; hydroxyethylenediaminetetraaceticacid, nitrilotriacetic acid (NTA); ethylenediaminetetraacetic acid(EDTA); N-hydroxyethyl-ethylenediaminetriacetic acid (HEDTA);diethylenetriaminepentaacetic acid (DTPA); and alanine-N,N-diaceticacid; and the like; and mixtures thereof. Still further sequestrantsinclude polycarboxylates, including, for example, polyacrylic acid,maleic/olefin copolymer, acrylic/maleic copolymer, polymethacrylic acid,acrylic acid-methacrylic acid copolymers, hydrolyzed polyacrylamide,hydrolyzed polymethacrylamide, hydrolyzed polyamide-methacrylamidecopolymers, hydrolyzed polyacrylonitrile, hydrolyzedpolymethacrylonitrile, hydrolyzed acrylonitrile-methacrylonitrilecopolymers, polymaleic acid, polyfumaric acid, copolymers of acrylic anditaconic acid, phosphino polycarboxylate, acid or salt forms thereof,mixtures thereof, and the like.

Further, unlike conventional equilibrium based performic acidcompositions, the present compositions can also be free of, orsubstantially free of surfactants. This is especially advantageous forcompositions incorporating C5 to C18 peroxycarboxylic acids. That is,under perhydrolysis conditions, the C5-C18 peroxycarboxylic acid anionsgenerated are water soluble. If the anions (e.g. peroxycarboxylicacid-forming compositions) are acidified for end use applications, theconcentrations of peroxycarboxylic acids are below the water solubilitylimit of the peroxycarboxylic acids. Thus, couplers are not needed tocouple the peroxycarboxylic acids in solution.

Additional Functional Ingredients

The compositions may also include additional functional ingredients.Additional functional ingredients suitable for use in the presentcompositions include, but are not limited to, acidulants, hydrotropes,dispersants, antimicrobial agents, optical tracers, solidificationagent, aesthetic enhancing agent (i.e., colorant (e.g., pigment),odorant, or perfume), among any number of constituents which can beadded to the composition. For example, suitable functional ingredientsfor various embodiments of the invention are hydrotropes, which may bedesired for producing clear compositions or dispersants which are moreefficient in producing homogeneous dispersions. Such adjuvants can bepreformulated with the present compositions or added to the compositionsafter formation, but prior to use. Additionally, the present inventionmay include optional use of an acidity source either prior to thereaction or after the reaction's completion. As one skilled in the artwould appreciate, use of an acid source prior to the reaction wouldincrease the kinetics of the reaction and/or decreases the heatingrequirements, while the addition of an acid source post-reaction woulddrive the pH of the performic acid below the pKa of formic acid, thusincreasing the stability of the composition. The compositions can alsocontain any number of other constituents as necessitated by theapplication, which are known and which can facilitate the activity ofthe present compositions.

Exemplary additional functional ingredients are disclosed in U.S. patentapplication Ser. No. 14/972,308 titled “Mixture Comprising Formic AcidHydrogen Peroxide, Methods of Generating the Mixture, and Use of theMixture for Antimicrobial Control” and Ser. No. 14/973,389 titled “InSitu Generation of Peroxyformic Acid through Polyhydric AlcoholFormate”, each of which are herein incorporated by reference in theirentirety.

In some embodiments, the performic acid compositions may include astabilizing agent, which is not required for formulation of theperformic acid compositions but may provide benefits for mixed performicacid compositions according to the invention. Such stabilizing agentsincluding for example phosphonic acids and phosphonate salts such asHEDP, may be particularly suitable for use of the mixed performic acidcompositions for use at high temperatures.

System for Making on-Site Performic Acid Compositions

In some aspects, the present invention relates to an adjustablegenerator apparatus or system for on-site generation of performic acidchemistries. The system produces performic acid forming compositionsaccording to the disclosure presented herein. Performic acid formingcompositions refer to the generation of performic acid (including mixedperacids comprising performic acid) in situ, in a non-equilibriumreaction.

In some aspects, the system for on-site generation of performic acidforming compositions may comprise, consist of and/or consist essentiallyof an apparatus including an inlet (or at least two inlets, or at leastthree inlets), a length of pipe, at least one heating device, and anoutlet for dosing the generated chemistry from the length of pipe. Insome aspects, the system may optionally include a mixer or mixing devicewithin the length of pipe. In some aspects, the system may optionallyinclude a cooling segment or loop. In some aspects, the system mayoptionally include at least one measurement device. In some aspects, thesystem may optionally include a control system. In some aspects, thesystem may optionally include safety devices.

Inlet

In some aspects, the invention consists of at least one inlet throughwhich reagents are supplied to the length of pipe. In embodiments whereonly one inlet is present, the reagents are mixed prior to the inlet.

In further embodiments of the invention, at least two inlets arepresent, wherein each reagent enters the length of pipe via itsindividual inlet. In such embodiments having at least two inlets, theinlets may be separated by a length of pipe to allow sequential additionof the reagents. In some embodiments a first inlet doses formic acid(and blends of formic acid) to the reactor and a second inlet doses thehydrogen peroxide source to the reactor. In such an embodiment, one ofthe inlets may further be used to flush the system with water. Inembodiments of the invention, the formic acid source and the oxidizingagent are introduced to the length of pipe in a ratio from about 1:1 toabout 5:1, preferably from about 2:1 to about 40:1, and preferably about20:1.

In further embodiments of the invention, at least three inlets arepresent, wherein each reagent enters the length of pipe via itsindividual inlet as well as a third inlet used for flushing the systemwith water, adding a corrosion inhibitor, biocide or additionalfunctional component to the length of pipe. In such embodiments havingat least three inlets, the inlets may be separated by a length of pipeto allow sequential addition of the reagents. In some embodiments afirst inlet doses formic acid to the reactor, a second inlet doses thehydrogen peroxide source to the reactor, and a third inlet allows waterto be flushed through the system and/or provides additional componentssuch as a corrosion inhibitor or biocide. Alternatively, a third inletmay be placed upstream of the first and/or second inlets so as to flushthe inlets and the remainder of the system with water. In still furtherembodiments of the invention, at least four inlets are present, whereineach reagent enters the length of pipe via its individual inlet as wellas a third inlet used for an additional peroxycarboxylic acid, and afourth inlet used for flushing the system with water, adding a corrosioninhibitor, biocide or additional functional component to the length ofpipe. In such embodiments having at least four inlets, the inlets may beseparated by a length of pipe to allow sequential addition of thereagents.

In embodiments of the invention, the formic acid source and theoxidizing agent are introduced to the length of pipe in a ratio fromabout 1:1 to about 5:1, preferably from about 2:1 to about 40:1, andpreferably about 20:1.

In a further aspect of the invention, the inlet temperature isapproximately that of ambient temperature. However, as one skilled inthe art would appreciate, a higher inlet temperature would reduce oreliminate the power required for heating and therefore reduce the riskof exceeding the decomposition temperature of the performic acid. Insome aspects, the inlets may have different temperatures. For example,in embodiments where the formic acid and the hydrogen peroxide sourceare dosed to the system via separate inlets, the formic acid sourceinlet may have a higher inlet temperature than the hydrogen peroxideinlet.

According to the embodiments of the invention, flow direction throughthe system may be upward, downward, or lateral. However, as one skilledin the art would appreciate, flow direction may be dependent on theprocess and stream variables such as density, temperature, and pressure,as well as external mechanical considerations such as pumping power. Ina preferred embodiment of the invention the second inlet which dosesoxidizing agent to the system has a downward flow.

In a further aspect of the invention, the inlets may need to undergodegasification in order to remove dissolved gases from the liquidstreams. As one skilled in the art would appreciate, degasification mayneed to occur for a number of reasons and without seeking to be limitedto a particular theory of invention, gasification may occur in thisapplication to remove dissolved gases from liquids that are possiblyair-or-oxygen sensitive or to avoid cavitation of pumping systems in adownstream process.

In some embodiments of the invention, dilution of the reagents does notoccur.

Length of Pipe

In some aspects of the invention, the reaction occurs within a length ofpipe which meets the hydraulic requirements of the performic acidreaction kinetics. As referred to herein, the pipe refers generally tothe length of a body within which the reaction occurs and is contained.Pipe should be understood to include a length of tubing or otherreceptacle suitable for containing the flow of the reaction for theperformic acid reaction kinetics according to embodiments of theinvention. Although not intending to be limited by a particular theoryof the invention, the kinetics of the reaction according to theinvention are pH, concentration, flow rate, and/or temperaturedependent, and the reaction begins producing yield in the order ofseconds to minutes. In some aspects of the invention, the reaction canproduce at least about 2% performic acid instantaneously, at least about4% performic acid within 1 minute, and at least about 8% performic acidwithin 2 minutes, and at least 15% performic acid within 30 minutes.Although not intending to be limited by a particular theory of theinvention, the kinetics of the reaction according to the invention arepH, concentration, flow rate, and/or temperature dependent, and thereaction can reach maximum yield in the order of seconds to minutes. Insome aspects the reaction can reach maximum performic acid yield withinabout 15 seconds, within about 30 seconds, within about 1 minute, orwithin about 2 to about 5 minutes.

The length of pipe may be designed in a variety of ways, including forexample shape, size, temperature, and material. According to anembodiment of the invention, the length of pipe may be of a given innerdiameter and is constructed of a material that is not readily corrodedand/or damaged by the presence of formic acid, hydrogen peroxide, and/orperformic acid(s). According to further embodiments, the length of pipeis constructed of a material that is not readily corroded and/or damagedby the presence of formic acid, hydrogen peroxide, performic acid(s),additional peracids and corresponding carboxylic acids, and/oradditional functional ingredients, such as optional stabilizers andadditional functional ingredients within the formulation for generatingthe performic acid.

In some embodiments, the length of pipes do not include for examplecopper, chromium, brass, and/or iron. Certain varieties of stainlesssteel are also to be avoided, for example, SS304. In a preferredembodiment of the invention, the length of pipe is constructed fromSS316 and/or SS316L. In a preferred embodiment of the invention, thelength of pipe is constructed from Polytetrafluoroethylene (PTFE) whichis a synthetic fluoropolymer of tetrafluoroethylene. However, oneskilled in the art will appreciate that other suitable materials areavailable.

In general the length of pipe is not effectively limited by pressure ofthe system due to the open system design of the generators according toembodiments of the invention. However, it is desirable that the pipe maybe designed to accommodate the potential occurrence of a runawayreaction based upon the material of the pipe. Preferably the pipe isdesigned to accommodate pressures of at least 20 PSI, at least 40 PSI,at least 50 PSI, at least 100 PSI, at least 150 PSI, at least 500 PSI,at least 1000 PSI, at least 2000 PSI, or greater, including all rangestherein. In an aspect, as one skilled in the art will ascertain, thepressure of the system is controlled so as not to exceed the burstpressure of any material employed for the length of pipe of thegenerator or apparatus of the invention. Beneficially, additionalcomponents of the generator or apparatus may optionally include pressurerelief valves, rupture disks, or the like to control the pressure of theopen system.

In some aspects of the invention, the flow through the pipe occurs at arate of about 0.1 mL/minute to about 100 mL/min, preferably about 10mL/min to about 50 mL/min, preferably about 20 mL/min to about 40mL/min. In an aspect of the invention, higher flow rates can be achievedby employing the apparatuses in parallel. In an aspect of the invention,higher flow rates can be achieved by turbulent flow systems. However, insome aspects, laminar flow systems are provided and may be combined witha mixer or mixing device contained within the length of pipe. In anaspect of the invention, it is preferred that flow through the pipe hasa laminar flow pattern, i.e., flow have a Reynolds number of less thanabout 2040 in order to allow for uniform heating.

In some embodiments, the length of pipes may be increased to enhance theresidence time of the reaction for generating the peroxyformic acid inthe generator according to the invention. In an exemplary embodiment,the length of the pipes may be at least 1 foot, at least about 10 feet,at least about 50 feet, or at least about 90 feet. In an embodiment acoiled length of pipes provides for increased length and residence timefor the reaction without occupying additional space for the length ofpipes of the generator. These and other modifications are includedwithin the scope of the disclosure.

Heating Device

In an aspect of the invention, heat is provided to the system throughthe use of at least one heating device. In a further aspect of theinvention, heat is provided to the system through the use of at leasttwo heating devices. Suitable heating devices include for example,cartridge, heat exchanger, heat blanket, steam jacket, solar panels,steam preheat, an electrical source, a heat wrap, or combinationsthereof, each of which may be referred to herein as heating device.

In a preferred embodiment of the system, heat is provided to the systemin an amount sufficient to raise the temperature of the reagents toaccelerate the reaction and to a temperature not exceeding thedecomposition temperature of performic acid, or about 200° C. Morepreferably, heat is provided to the system in an amount sufficient toraise the temperature of the reagents to a temperature not exceeding180° C. In an aspect, the temperature increase will increase the rate ofreaction, however, as one skilled in the art will ascertain, thestability of the performic acid is not to be compromised by increasingthe temperature, including at a temperature not exceeding 200° C.

In some aspects of invention, the location of the heating device(s) iswithin a section or sections of pipe. In some aspects, the location ofthe heating device(s) is wrapped in insulation to eliminate the amountof heat lost to the environment, which may be on the inside and/oroutside of the length of pipe. In such aspects, the insulation heatingdevice may span all or a portion of the length of pipe.

In a preferred aspect, a heating device includes a cartridge locatedwithin the length of pipe. Such cartridge has a diameter less than theinner diameter of the pipe. According to a preferred embodiment of theinvention, it is preferable to maintain the difference between thecartridge's diameter and the pipe's inner diameter less than about 5inches, more preferable less than about 3 inches, and more preferablyless than about 1.75 inches. Furthermore, the system possesses a givencross sectional area that is available for heat transfer, defined as theinner cross sectional area of the pipe minus the cross sectional area ofthe cartridge heater. However, one skilled in the art will appreciatethat the optimal area available for heat transfer will depend on thetemperature of the inlet(s), flow rate, heater length, etc. Although notintending to be limited by a particular theory of the invention, alarger cross sectional area is viable with a lower flow rate because therate of heat transfer is lower, resulting in a lower temperature at thesurface of the cartridge heater. In a further embodiment of theinvention, heaters may be employed in series or in parallel in order tominimize the heater's temperature. In a further embodiment of theinvention, the heat provided to the system is controlled via anelectronic control system.

In some aspects of the present invention, wherein the heating device isa cartridge, the available volume of the pipe is affected. The availablevolume is thus defined as the volume held within the pipe at a giventime minus the volume occupied by the heating cartridge. In a preferredembodiment, the volume of the system is increased by employing systemsin parallel rather than increasing pipe size and or volume.

In a further aspect of the invention, uniform heating of the reagentswithin the length of pipe is desired, such uniform heating is influencedby the radial distance from the outside of the heater surface to theinner surface of the pipe, where a larger distance leads to a highergradient, and the length of the heating zone, where longer contact withheater leads to a lower gradient. As one skilled in the art willappreciate, these influences have inverse effects on the heat gradientand will thus appreciate the weighing of these influences whendetermining the dimensions of the heating devices.

In a further aspect of the invention, uniform heating of the reagentswithin the length of pipe is not feasible and/or desired. In suchembodiments, staged heating may be employed such that in a first sectionof the length of pipe the temperature of the reagent(s) is increased ata desired increment (e.g. 5-10 degrees C.), thereafter in a secondsection of the length of pipe the temperature of the reagent(s) isincreased at a desired increment (e.g. 5-10 degrees C.), and so on.

In some aspects of the invention, the power required by the heatingdevice and accompanying pumps preferably does not exceed about 100 wattsfor flow rates of 50 mL/min. More preferably, the power does not exceed80 watts and more preferably, the power does not exceed 50 watts.

Heating can also be controlled, irrespective of the power of the heater,through control cycles that involve cycles of time where the heater ison for cycles of time. In an aspect, the controlled cycles may includethe heater being on for about 10-100% of the cycle of the generator. Insome embodiments, cycles of time can be from about 2 seconds to about100 seconds. In another aspect, heating can also be controlled by PIDloops with proportionality constants directly correlating to the flowrate. These and other modifications are included within the scope of thedisclosure.

Outlet

In a preferred aspect of the present invention, an outlet is present. Inan aspect of the invention the outlet provides the performic acidchemistries to a downstream process as desired by the controller and/oruser. In an aspect, the outlet provides the performic acid chemistriesto a storage reservoir. In an aspect, the outlet provides the performicacid chemistries to a cooling system. In an aspect of the invention, theconcentration of the performic acid at the outlet is at least 1 wt-%,more preferably at least 5 wt-% at the outlet.

Mixer

In a preferred aspect of the present invention, at least one mixer ormixing device is present within the length of pipe. The mixed or mixingdevice can include any suitable forms for the mixer or mixing device,such as an impeller or any type of static mixer. In some aspects, themixer or mixing device is present in the length of pipe at a pointdownstream from the addition of the hydrogen peroxide source. In such anembodiment the combined reagents of at least the formic acid and thehydrogen peroxide source are combined via mixing. As one skilled in theart will ascertain, under laminar flow conditions it is desirable tohave a mixer or mixing device. However, a system designed to provideturbulent flow does not require a mixer or mixing device. In someembodiments, either a laminar or turbulent flow systems employs a mixeror mixing device.

Cooling System

In another aspect of the invention, the system may include a coolingsystem or a cooling loop/segment on the reaction vessels. A coolingsystem may be in combination with a safety mechanism and/or ameasurement device of the system. It may be desirable to have componentsof the system under temperature controls. As one skilled in the art willappreciate, exothermic reactions may degrade the reagents according tothe generation of the performic acid compositions of the invention. Inan aspect, the cooling system stabilizes the performic acid compositionand thereby increases shelf-life by lowering the temperature to atemperature to that of freezing or below freezing. In addition,according to an embodiment of the invention, the system has at least onemechanism to cool components of the system. Multiple cooling mechanismsmay be used in either series or parallel. Such mechanisms may include,for example, a quenching mode, increased surface area, cooling jacket,venting systems, cold finger, and the like. In a further aspect of theinvention, the outlet of the performic acid(s) is cooled by using heatexchange, refrigeration sleeve, blower, cooled vessel, etc.

Measurement Devices

In some aspects of the disclosure, the system for on-site generation ofperformic acid forming compositions may include at least one measurementdevice or a plurality of measurement. Such measurement devices are thosesuitable to measure one or more reaction kinetics or system operationsfor the generation of performic acid forming compositions, including forexample devices to measure conductivity, weight, flow (e.g. flow metersor switches), pH, pressure, temperature and combinations thereof. Suchmeasurement devices may measure the system's inlets, piping, outlets,etc.

Examples of additional suitable measurement devices include, forexample, conductivity sensors, thermometers, out of product alarms,peroxide monitors, IR/UV/VIS spectroscopy, NMR and pressure switches.For example, in an embodiment of the invention, temperature is monitoreda various points in the apparatus to ensure consistent heating at atemperature not exceeding the flash point of the performic acid.Additionally, in an embodiment of the invention pressure is monitored toensure there is not an occurrence of a “runaway reaction.” This pressuremonitoring could be accomplished by use of a differential pressuresensor within a feedback control loop, wherein in a pressure readingexceeding a set point would cause a safety release valve and/or rupturedisk to be employed or venting to occur.

In another embodiment of the disclosure, temperature is monitored forindication of a run-away reaction. Temperature probes can be placedupstream and downstream of the reaction. If the downstream temperatureis higher than the upstream temperature then run away reaction hasoccurred.

In a further embodiment of the disclosure, flow rate is monitored witheither a pressure sensor or an orifice plate/meter. Furthermore,conductivity may be monitored to determine the concentration of productsin the stream and/or the concentration of the performic acid at theoutlet. In a further embodiment, generation rates, temperatures, andconcentrations can all be optimized via monitoring systems and/orcontrollers. Additionally, an embodiment of the invention would allowfor rinsing of the apparatus so that residual chemistry does not remainin the system.

A further suitable measurement device is an automatic titrator tomeasure the PFA active and Peroxide residual, such as disclosed in U.S.Pat. No. 8,980,636, which is incorporated herein by reference. Stillfurther examples of suitable measurement devices are disclosed herein,in addition various embodiments of those disclosed in U.S. patentapplication Ser. No. 12/108,202, and U.S. Pat. No. 7,547,421, bothentitled Apparatus and Method for Making Peroxycarboxylic Acid, whichare herein incorporated by reference in their entirety.

Control System

In some aspects, the system for making on-site performic acid chemistryformulations further comprises an optional controller or softwareplatform. The software platform provides a user or system to select ageneration mode for a desired performic acid formulation for on-sitegeneration. As a result, use of the system for on-site performic acidchemistry generation provides significant user flexibility to generatechemistries for particular user-identified purposes. For example, thecontroller or control software for operation of the system may permit auser or system to select both the performic acid formulation and thedesired volume and dosage concentration of the formulation for on-sitegeneration. In a further aspect, the control software may determine thetiming, sequencing and/or selection of feeding raw materials (e.g.reagents) into the system, mixing time and total reaction time requiredfor production of the user- or system-selected performic acidformulation. In a still further aspect of the invention, the controlsystem includes the above described measurement devices.

According to the invention, the controller may further include amechanism for manually starting/stopping any of the same functions,including for example a manual switch panel for the same. In addition tomanual controls, such as a manual switch panel, the controllerpreferably has buttons or other means for selecting particularembodiments according to option displayed by the control softwareplatform. An embodiment of the controller may further include a displayscreen to assist a user in selecting a generation mode for a desiredperformic acid formulation and any other options for user selection asone skilled in the art will ascertain based upon the description of theinvention. Concomitant with the control software are user-friendlyinstructions for use displayed on the display screen (or the like).

In an aspect of the invention, the control software utilizes a controlsoftware algorithm to maximize on-site active chemistry yield andprovide safe operating conditions for the reactor vessel(s) of thesystem. The control software permits user-identified chemistryproduction to be run in one or multiple reaction vessels and to properlysequence reactions to obtain active chemistries.

In an aspect of the invention, the control software controls thetemperature of the reaction to form the peroxyformic acid, namelycontrols the heating device of the on-site generator.

Examples of suitable controllers are disclosed herein, in additionvarious embodiments of those disclosed in U.S. patent application Ser.No. 12/108,202, and U.S. Pat. No. 7,547,421, both entitled Apparatus andMethod for Making Peroxycarboxylic Acid, which are herein incorporatedby reference in their entirety.

In another aspect of the invention, the system may include a data outputmeans for sharing information related to the performic acid formingcompositions and/or performic acid formulations generated according tothe system. For example, an information backbone may be used to bothcollect and disseminate data from the process of generating theperformic acid formulations including, for example, compositionconsumption, dispensing or usage, and additional formulationproduction-related data. Such data may be generated in real-time and/orprovided in a historical log of operational data detectable or storableby a user or system. In an embodiment of the invention a user or systemis able to monitor usage and performance, including for example,chemistry dispensing, managing chemistry distribution to variouspoint-of-use applications, communication with system operators tocontrol and monitor chemistry dispensing, allocation and/or formulationand the like. According to an additional embodiment of the invention, auser or system is able to control systems, including program systems,remotely. Control systems also include safety shut off of the heater andpumps at no flow and shut offs when monitoring devices indicate arun-away reaction.

According to an aspect of the invention, any system operations suitablefor use with the invention may be controlled and/or monitored from aremote location. Remote system operations control and/or monitoring mayfurther include the system updates and/or upgrades. According to anaspect of the invention updates and/or upgrades to system operations maybe downloaded remotely. These and other embodiments of data outputmeans, information sharing, remote system operations and the like, whichmay be adapted for use with the present invention, are furtherdescribed, for example, in U.S. Pat. Nos. 7,292,917, 6,895,307,6,697,706 and 6,377,868 and U.S. Patent Publication Nos. 2005/0102059,2005/0065644, 2004/0088076, 2003/0195657 and 2003/0195656, which arehereby expressly incorporated by reference including, withoutlimitation, the specification, claims, and abstract, as well as anyfigures, tables, or drawings thereof.

In another aspect of the invention, the data output for sharinginformation related to the compositions according to the system maycoordinate multiple systems on at a single site. According to thisembodiment of the invention, information sharing between the multiplesystems may take places place using any communications network capableof coupling one or more systems according to the present invention,including for example, using a server computer and a database.

Safety Devices

In some aspects of the invention, the system may include a variety ofsafety mechanisms. Exemplary on-site safety feedback mechanisms for asystem are disclosed in further detail in U.S. Patent Publication No.2009/0208365, which is hereby expressly incorporated by referenceincluding, without limitation, the specification, claims, and abstract,as well as any figures, tables, or drawings thereof. Various safetymechanisms can measure pressure, temperature, difference in pressure,difference in temperature, or a combination thereof and provide aperceptible signal if one or more of these increases above apredetermined level. In an aspect, the level of pressure, temperature,difference in pressure, difference in temperature, or a combinationthereof at which safety system provides a perceptible signal can beselected to allow intervention to avoid undesirable or unsafeconditions. In a further aspect of the invention, the system is designedto accommodate at least 5 times the pressure of the system (i.e. designpressure), more preferably at least 3 times the pressure of the system,and more preferably at least 1.5-2 times the pressure of the system. Ina further aspect, the system is designed for explosion safety ratings,such as for example, according to the American Petroleum Institute(API). In a further aspect of the invention, the system may includepressure relief valves and/or rupture discs to control the pressure ofthe system.

Illustrated Embodiments

According to an embodiment of the invention, as shown in FIG. 1, a useror process controller input selects both the performic formulation andthe flow rate and such input information is loaded into the system.Control software, including a software algorithm, may be used tocalculate the flow rates required for the particular concentration. Rawmaterials are fed into the system under controlled flow rates andreaction times.

As shown in the exemplary and non-limiting FIG. 1, a user or processcontroller input (e.g. peracid and volume selection) is provided, and anadjustable biocide formulator system according to the invention isemployed to provide raw materials (reagents) to feed a length of pipeunder heated conditions which are controlled reaction conditions. Thedepicted system may employ a variety of measurement devices providingfeedback to the system. Measurement devices according to the inventionmay include devices suitable to measure one or more reaction kinetics orsystem operations for the generation of performic acid formingcompositions, including for example, devices to measure conductivity,weight, flow, pH, pressure, temperature and combinations thereof. Afurther suitable measurement device is an automatic titrator to measurethe PFA active and Peroxide residual, such as disclosed in U.S. Pat. No.8,980,636, which is incorporated herein by reference. Such measurementdevices may measure the system's inlets, pipes, outlets, heatingdevices, etc. Exemplary measurement devices may include the monitoringand reporting of the temperature and pressure of the length of pipe, thetemperature and pressure of the materials at the inlet(s), thetemperature and pressure of the materials at the outlet(s), and flowrate. Additional measurement devices may control: the flow rate; pH ofraw materials and solutions in reaction; and the like. As one skilled inthe art will ascertain, such regulators, measurement devices, sensorsetc. are well known and not intended to limit the embodiments of thepresent invention.

In addition, measurement devices may be used to activate alarmsindicating the system and/or methods of generating the performic acidforming compositions are outside of desirable ranges; for example,measurement devices may be used to generate out of product alarms (e.g.indicating a raw starting material is ‘low’ or out of product entirely).An exemplary measurement device for such an alarm would measure theavailability of a particular raw material (premix or the like) from thevolume of such raw material in a drum.

Optionally, for generation of a performic acid formulation (as opposedto the anion peroxycarboxylic acid forming compositions), the stabilityof the reaction intermediates may be enhanced by adding an acid oraqueous acidic solution. The system provides the user or processcontroller the desired performic acid formulation for use in a cleaningprocess, including without limitation, antimicrobial, bleaching, andsanitizing and/or anti-scaling applications. In addition, various dataoutput and information sharing methods may optionally be employedaccording to the methods and systems of the invention.

According to an embodiment of the invention shown in FIG. 2, reagentsenter the length of pipe 2 through at least three depicted inlets 1, 1′,10. In an aspect, reagents include formic acid source and oxidizingagent. In a further aspect, an inlet is employed for flushing a systemwith water as needed. In an exemplary embodiment depicted by FIG. 2, aformic acid source is added at 1 or 1′ (and a water flush is suitablefor use at 1′ or 1), and an oxidizing agent is added at 10. Suchreagents are then contacted with at least one heating device 3, 3′,which catalyzes the reaction of the performic acid source and theoxidizing agent to form the desired product. As depicted, the heatingdevice is shown in distinct forms, including a heating cartridge 3,which penetrates through one end of the length of pipe and is disposedthrough at least a portion of the inner diameter of the pipe 2. Anadditional heating device is shown 3′ as an insulating heater to atleast a portion of the length of pipe. Without being limited accordingto the depicted embodiments, the insulating heater 3′ could in thealternative or addition be wrapped around the outside of the pipe 2(e.g. on the outside of the insulation of the pipe 8). Further depictedin the non-limiting depicted embedment are various optional measurementdevice(s) 5 which may be in connection with a control system 6. Anynumber of measurement device(s) 5 can be included in a system.Additionally the system may include safety devices 7 and/or insulationof the pipe 8 and/or a mixer 9. The mixed as depicted shows an impeller,however in many aspects a static mixer is employed. The depiction of 9is a non-limiting depiction of a mixer. The performic acid formingcompositions or performic acid compositions of the present invention arethen supplied via an outlet 4 to either an optional downstream coolingsystem, storage reservoir or to the desired use.

According to an embodiment of the invention shown in FIG. 3, reagentsenter the length of pipe 2 through at least two depicted inlets 1, 10.In an aspect, reagents include formic acid source and oxidizing agent.In an exemplary embodiment depicted by FIG. 3, a formic acid source isadded at 1 and an oxidizing agent is added at 10. Such reagents are thencontacted with at least one heating device 3, 3′, shown as a heatingcartridge 3 penetrating through one end of the length of pipe 2 and isdisposed through at least a portion of the inner diameter of the pipe 2.An additional heating device is shown 3′ as an insulating heater to atleast a portion of the length of pipe. Further depicted in thenon-limiting depicted embodiment are various optional measurementdevice(s) 5 which may be in connection with a control system 6. Anynumber of measurement device(s) 5 can be included in a system.Additionally the system may include safety devices 7 and/or insulationof the pipe 8 and/or a mixer 9. The performic acid forming compositionsor performic acid compositions of the present invention are thensupplied via an outlet 4 to either an optional downstream coolingsystem, storage reservoir or to the desired use.

According to an embodiment of the invention shown in FIG. 4, a stagedheating system is set forth for use according to the invention. A lengthof pipe 2 with at least two depicted inlets 1, 10 and provided to addreagents including formic acid source at inlet 1 and oxidizing agent atinlet 10. Such reagents are then contacted with at least one heatingdevice 3, 3′, shown as a heating cartridge 3 penetrating through one endof the length of pipe 2 and is disposed through at least a portion ofthe inner diameter of the pipe 2. As depicted a series of three stagedheating portions of the length of pipe are provided along with aninsulating heating layer 3′ to at least a portion of the length of pipe.Further depicted in the non-limiting depicted embodiment are variousoptional measurement device(s) 5 which may be in connection with acontrol system 6. Any number of measurement device(s) 5 can be includedin a system. Additionally the system may include safety devices 7 and/orinsulation of the pipe 8 and/or a mixer 9. The performic acid formingcompositions or performic acid compositions of the present invention arethen supplied via an outlet 4 to either an optional downstream coolingsystem, storage reservoir or to the desired use.

According to an embodiment of the invention shown in FIG. 9, reagentsenter the length of pipe 2 through at least two depicted inlets 1, 10.In an aspect, reagents include a formic acid source and oxidizing agent.In an exemplary embodiment depicted by FIG. 9, a formic acid source isadded at 1 and an oxidizing agent is added at 10. The formic acid sourceis then contacted with at least one heating device 3, 3′, shown as aheating cartridge 3 penetrating through one end of the length of pipe 2and is disposed through at least a portion of the inner diameter of thepipe 2. An additional exemplary heating device is shown 3′ as aninsulating heater to at least a portion of the length of pipe (which canfurther extend through or along any desired length of the pipe 2, anddepicted in this figure as extending only a portion of the pipe 2).Further depicted in the non-limiting embodiment shown in the figure arewater inlet 1′ which may be used to flush the inlets 1, 10 and thelength of pipe 2 with water. Additionally, the system may includevarious optional measurement device(s) 5 which may be in connection witha control system 6. Any number of measurement device(s) 5 can beincluded in a system and situated in various locations throughout.Further, the system may include safety devices 7 and/or insulation ofthe pipe 8 and/or a mixer 9 which can be included in a system andsituated in various locations throughout. The performic acid formingcompositions or performic acid compositions of the present invention arethen supplied via an outlet 4 to either an optional downstream coolingsystem, storage reservoir or to a desired use. Beneficially, as depictedin FIG. 9, the generator employs a downward flow direction through thesystem to more readily contact the reagents for the in-situ reaction andenable the near instantaneous generation of performic acid. The depictedembodiment employing a downward flow direction of reagents, namely theoxidizing agent 10, adapts to the density of the reagent withoutrequiring (or minimally requiring) external mechanical considerationssuch as pumping power. In a preferred embodiment of the invention, suchas shown in FIG. 9, at least the second inlet (dosing the oxidizingagent 10) to the system has a downward flow.

According to an embodiment of the invention shown in FIG. 10, reagentsenter the length of pipe 2 through at least two depicted inlets 1, 10.In an aspect, reagents include a formic acid source and oxidizing agent.In an exemplary embodiment depicted by FIG. 10, a formic acid source isadded at 1 and an oxidizing agent is added at 10. The formic acid sourceis then contacted with at least one heating device 3, as shown as aheating cartridge 3 penetrating through one end of the length of pipe 3and is disposed through at least a portion of the pipe 2. Furtherdepicted in the non-limiting embodiment shown in FIG. 10 are water inlet1′ which may be used to flush the inlet 1 and the length of pipe 2 withwater. Degasification may occur at 11 via any suitable method.Additionally, the system may include various optional measurementdevice(s) 5 which may be in connection with a control system 6. Anynumber of measurement device(s) 5 can be included in a system andsituated in various locations throughout. Further, the system mayinclude safety devices 7 and/or insulation of the pipe 8 and/or a mixer9 which can be included in a system and situated in various locationsthroughout. The performic acid forming compositions or performic acidcompositions of the present invention are then supplied via an outlet 4to either an optional downstream cooling system, storage reservoir or toa desired use. Beneficially, as depicted in FIG. 10, the generatoremploys a downward flow direction through the mixer 9 to more readilycontact the reagents for the in-situ reaction and enable the nearinstantaneous generation of performic acid. The depicted embodimentemploying a downward flow direction of reagents, which are mixed instream prior to reaching the mixer 9 adapts to the density of thereagents without requiring (or minimally requiring) external mechanicalconsiderations such as pumping power.

According to an embodiment of the invention shown in FIG. 12, reagentsenter the length of pipe 2 through at least two depicted inlets 1, 10.In an exemplary embodiment depicted by FIG. 12, a formic acid source isadded at 1 and an oxidizing agent is added at 10. The formic acid sourceis then contacted with at least one heating device 3 disposed through atleast a portion of the pipe 2. Further depicted in the non-limitingembodiment shown in FIG. 12 is an outlet 4 to either an optionaldownstream cooling system, storage reservoir or to a desired use.Beneficially, as depicted in FIG. 12, the generator employs a downwardflow direction of the oxidizing agent through the mixer 9 to morereadily contact the reagents for the in-situ reaction and enable thenear instantaneous generation of performic acid. The depicted embodimentemploying a downward flow direction of the oxidizing agent reagents,which are mixed in stream prior to reaching the mixer 9 adapts to thedensity of the reagents without requiring (or minimally requiring)external mechanical considerations such as pumping power.

Although not depicted in every embodiment of the invention shown in thefigures, various additional inlets may be present, such as for examplewater inlets to flush an inlet and/or a length of pipe 2 with water, orinlets for providing additional components include biocides and/orcorrosion inhibitors, or still further additional inlets for providingadditional peroxycarboxylic acids (such as those which may containformic acid). Still further, degasification may occur at 11 via anysuitable method within any of the depicted embodiments. Additionally,the systems may include various optional measurement device(s) 5 whichmay be in connection with a control system 6. Any number of measurementdevice(s) 5 can be included in a system and situated in variouslocations throughout. Further, the system may include safety devices 7and/or insulation of the pipe 8 and/or a mixer 9 which can be includedin a system and situated in various locations throughout. Each of thesecomponents can be included in the generator according to invention,including in configurations depicted in each of the figures. Stillfurther, the various inlets and outlets can be configured with an upwardor lateral flow and still others configured with a downward flow.

Performic Acid Compositions

In some embodiments, the system according to the present inventionproduces performic acid forming compositions or performic acidcompositions for use in a variety of cleaning application. In someaspects, the present disclosure relates to performic acid formingcompositions. That is, the compositions are capable of generatingperformic acids in situ, in a non-equilibrium reaction. Performic acidgenerally has the formula CH₂O₃.

In an embodiment of the invention the performic acid formingcompositions comprise individual reagents combined according to theinvention. These reagents are described herein individually and includeat least source of formic acid and an oxidizing agent. Alternatively, asdescribed herein, there may be benefits to providing the reagents invarious premix formulations to decrease the number of reagents and/orincrease the simplicity of the invention.

Methods for Making on-Site Performic Acid Compositions

In some embodiments, the methods according to the present invention forproducing performic acid forming compositions or performic acidcompositions comprise, consist of and/or consist essentially ofproviding a formic acid source, providing an oxidizing agent, contactingsaid formic acid source and oxidizing agent to form the reactionmixture, heating said reaction mixture at a given flow rate to formperformic acid, and delivery said performic acid to a downstreamprocess. In a further embodiment, the methods according to the presentinvention for producing performic acid forming compositions or performicacid compositions comprise cooling the performic acid. In a furtherembodiment, the methods according to the present invention for producingperformic acid forming compositions or performic acid compositionscomprise measuring variables including conductivity, temperature,product levels, concentration, IR/UV/VIS spectroscopy, pressure, flowrate, etc. In a further embodiment, the methods according to the presentinvention for producing performic acid forming compositions or performicacid compositions comprise controlling the system through use of acontrol system. In a further embodiment, the methods according to thepresent invention for producing performic acid forming compositions orperformic acid compositions comprise employing safety devices.

Formic Acid Source

In an aspect of the invention, a formic acid source is provided to thesystem. The formic acid source used in the present methods can beprovided in any suitable way. In some embodiments, before the contactingstep, the formic acid can be provided in a composition that comprisesformic acid, e.g., an aqueous solution that comprises formic acid andadditional optional functional ingredients, such as a corrosioninhibitor. In other embodiments, before the contacting step, the formicacid can be provided in a composition that comprises a substance thatgenerates formic acid upon contact with an aqueous composition. Anysuitable substance that generates formic acid can be used in the presentmethods.

In an aspect, the formic acid source is an aqueous solution thatcomprises formic acid. In another aspect, the formic acid source is asalt of formic acid, such as formate, e.g., a sodium or ammonium salt offormate. In an aspect, the formic acid source is an ester alcohol, suchas ethyl formate, propylene formate, glycerol formate, etc.

In an aspect, the formic acid source is a composition that comprisesformic acid (or a salt of formic acid) and additional optionalfunctional ingredients, such as a corrosion inhibitor. Beneficially, theformic acid and corrosion inhibitor systems provide a corrosionprotected system. In such an embodiment, the concentration of thecorrosion inhibitors will be less than 10% of the formic acidcomposition, preferably less than % of the formic acid composition. Insome embodiments, the corrosion inhibitor can be a phosphate ester, aderivative of the phosphate ester, a diacid, a derivative of the diacid,a quat amine, a derivative of the quat amine, an imidazoline, aderivative of the imidazoline, an alkyl pyridine, a derivative of thealkyl pyridine, a phosphonium salt, a derivative of the phosphoniumsalt, or a combination thereof.

In an aspect, the formic acid source is a composition that comprisesformic acid (or a salt of formic acid) and additional percarboxylicacids and/or carboxylic acids, such as C1-C22 percarboxylic acids and/orcarboxylic acids, preferably C5-C22 percarboxylic acids and/orcarboxylic acids, to beneficially provide a blended formic acidcomposition to provide synergistic antimicrobial efficacy againstmicroorganisms. In such aspects, a mixture of peroxyformic acid, andadditional percarboxylic acids and/or carboxylic acids, such asperacetic acid or peroctanoic acid, such as disclosed in U.S. Pat. No.5,314,687 which is herein incorporated by reference in its entirety, areprovided. In such an aspect, the peracid mixture provides antimicrobialsynergy. In an aspect, the synergy of a mixed peracid system allows theuse of lower dosages of the peracids.

Oxidizing Agent

The compositions also include an oxidizing agent. The oxidizing agentmay include a peroxide source. In an aspect, the hydrogen peroxide is1-50% w/v hydrogen peroxide. Oxidizing agents suitable for use with thecompositions include the following types of compounds or sources ofthese compounds, or alkali metal salts including these types ofcompounds, or forming an adduct therewith: hydrogen peroxide,urea-hydrogen peroxide complexes or hydrogen peroxide donors of: group 1(IA) oxidizing agents, for example lithium peroxide, sodium peroxide;group 2 (IIA) oxidizing agents, for example magnesium peroxide, calciumperoxide, strontium peroxide, barium peroxide; group 12 (IIB) oxidizingagents, for example zinc peroxide; group 13 (IIIA) oxidizing agents, forexample boron compounds, such as perborates, for example sodiumperborate hexahydrate of the formula Na₂[B₂(O₂)₂(OH)₄].6H₂O (also calledsodium perborate tetrahydrate); sodium peroxyborate tetrahydrate of theformula Na₂B₂(O₂)₂[(OH)₄].4H₂O (also called sodium perboratetrihydrate); sodium peroxyborate of the formula Na₂[B₂(O₂)₂(OH)₄] (alsocalled sodium perborate monohydrate); group 14 (IVA) oxidizing agents,for example persilicates and peroxycarbonates, which are also calledpercarbonates, such as persilicates or peroxycarbonates of alkalimetals; group 15 (VA) oxidizing agents, for example peroxynitrous acidand its salts; peroxyphosphoric acids and their salts, for example,perphosphates; group 16 (VIA) oxidizing agents, for exampleperoxysulfuric acids and their salts, such as peroxymonosulfuric andperoxydisulfuric acids, and their salts, such as persulfates, forexample, sodium persulfate; and group VIIa oxidizing agents such assodium periodate, potassium perchlorate. Other active inorganic oxygencompounds can include transition metal peroxides; and other suchperoxygen compounds, and mixtures thereof.

In some embodiments, the compositions of the present invention employone or more of the inorganic oxidizing agents listed above. Suitableinorganic oxidizing agents include ozone, hydrogen peroxide, hydrogenperoxide adduct, group IIIA oxidizing agent, or hydrogen peroxide donorsof group VIA oxidizing agent, group VA oxidizing agent, group VIIAoxidizing agent, or mixtures thereof. Suitable examples of suchinorganic oxidizing agents include percarbonate, perborate, persulfate,perphosphate, persilicate, or mixtures thereof.

In some embodiments, the oxidizing agent includes hydrogen peroxide, ora source or donor of hydrogen peroxide. In other embodiments, theoxidizing agent includes a peroxide source selected from a percarbonate,a perborate urea hydrogen peroxide, PVP-peroxides and mixtures thereof.

Additional Optional Components

In an embodiment, the reagents described herein (e.g. formic acid and anoxidizing agent) may be combined with additional optional components. Inan aspect, the additional components can include a corrosion inhibitor.Corrosion inhibitors are additional molecules used in oil and gasrecovery operations. Corrosion inhibitors that may be employed in thepresent disclosure are disclosed in U.S. Pat. No. 5,965,785, U.S. PatentPublication No. 2010/0108566, GB Patent No. 1,198,734, WO/03/006581,WO04/044266, and WO08/005058, each of which are incorporated herein byreference in their entirety.

In an aspect, the additional components can include an additionalbiocide. Additional biocides may include, for example, a quaternaryammonium compound as disclosed in U.S. Pat. No. 6,627,657, which isincorporated herein by reference in its entirety. Beneficially, thepresence of the quaternary ammonium compound provides both synergisticantimicrobial efficacies with peracids, as well as maintains long termbiocidal efficacy of the compositions. In another embodiment, theadditional biocide may include an oxidizer compatible phosphoniumbiocide, such as tributyl tetradecyl phosphonium chloride. Thephosphonium biocide provides similar antimicrobial advantages as thequaternary ammonium compound in combination with the peracids. Inaddition, the phosphonium biocide is compatible with the anionicpolymeric chemicals commonly used in the oil field applications, such asthe methods of the fracking disclosed according to the invention. In apreferred aspect, the additional biocide is Gluteraldehyde, THPS, quatamine, and/or TTPC.

In an aspect, the additional components can include a friction reducer.Friction reducers are used in water or other water-based fluids used inhydraulic fracturing treatments for subterranean well formations inorder to improve permeability of the desired gas and/or oil beingrecovered from the fluid-conductive cracks or pathways created throughthe fracking process. Examples of commonly used friction reducersinclude polyacrylamide polymers and copolymers. In an aspect, additionalsuitable friction reducers may include acrylamide-derived polymers andcopolymers, such as polyacrylamide (sometime abbreviated as PAM),acrylamide-acrylate (acrylic acid) copolymers, acrylicacid-methacrylamide copolymers, partially hydrolyzed polyacrylamidecopolymers (PHPA), partially hydrolyzed polymethacrylamide,acrylamide-methyl-propane sulfonate copolymers (AMPS) and the like.Various derivatives of such polymers and copolymers, e.g., quaternaryamine salts, hydrolyzed versions, and the like, should be understood tobe included with the polymers and copolymers described herein.

Premix Formulations

In an embodiment, the reagents described herein (e.g. formic acid and anoxidizing agent) may be combined in a premix formulation to reduce thenumber of raw starting materials required for the methods andcompositions and further simplify the methods of the invention.According to such an embodiment the providing of premix formulationsensures consistent and stable delivery of reagents.

Premix formulations suitable for use according to the invention maycomprise, consist of and/or consist essentially of at least formic acidsource, a combination of formic and other C2-C18 carboxylic acids and,an oxidizing agent and mixtures thereof.

As one skilled in the art will ascertain, the use of premixes employsadditional functional ingredients for purpose of stabilizing the premixconcentrate for use in the compositions and methods according to theinvention. For example, hydrotropes, dispersing agents and/or othersolvents may be desirable for maintaining the solubility and stabilityof a particular concentrated premix. The use of any couplers ordispersing agent (such as a surfactant) within a premix formulation isdistinct from the use of surfactants in the conventional generation andstorage of performic acid chemistries, wherein couplers are critical toestablishing and maintaining a stable, clear solution of the generatedperformic acid chemistry.

According to the invention, the use of dispersing agents alone within aconcentrated premix formulation does not stabilize the premixcomposition. Rather the dispersing agents are provided in an amountsuitable for providing meta-stable performic acid compositions generatedfrom the premix after acidification, before further dilution forapplication. The most efficient dispersing agents were found to beanionic surfactants, and this type of surfactant is known to have highfoaming profile. For applications which involves mechanical actions(e.g. CIP sanitizing), the high foam property of the composition isundesirable. Thus, in addition to economic reason, it is preferred touse a minimum amount of the dispersing agent to achieve a meta-stableperformic acid composition to meet the application of use requirements.

According to an embodiment of the invention less than about 10 ppm,preferably less than about 9 ppm, less than about 8 ppm, less than about7 ppm, less than about 6 ppm, less than about 5 ppm, less than about 4ppm, less than about 3 ppm, less than about 2 ppm, or less than about 1ppm of a dispersing agent is included in the generated performic acidchemistry as a result of the use of a surfactant dispersing agent in aconcentrated premix formulation according to the invention. This isdistinct from the level of surfactants in use solutions of a traditionalperformic acid chemistry, where the amounts of surfactants are normallyin excess of about 50 ppm, in excess of about 60 ppm, in excess of about70 ppm, in excess of about 80 ppm, in excess of about 90 ppm, or inexcess of about 100 ppm.

According to an embodiment of the invention, the use of a solvent (e.g.ethanol) is an efficient way to make a stable premix composition.Solvents suitable for the concentrated premix formulations according tothe invention include, for example, organic solvents such as alcohol,ether or ketone. Preferably, the solvent is a water soluble alcohol,such as ethanol, methanol, propanol, isopropanol and/or butanol. As oneskilled in the art will ascertain the various isomers of the solvents,including alcohols, are further included within the scope of thesolvents suitable for use with the concentrated premix formulations ofthe invention.

Beneficially, the use of concentrated premix formulation still does notrequire the use of any chelators and/or stabilizers. As a result,regardless of whether individual reagents or concentrated premixformulations are utilized according to the invention, both the reagentsand the performic acid compositions generated according to the inventionprovide sustainable chemistries as a result of the elimination of theuse of various stabilizers and/or additional amounts of chemistryrequired to drive the formation of traditional performic acid chemistry.As a result of reduced input of reagents for the compositions accordingto the invention (e.g. resulting from the use of a non-equilibriumreaction) there is a significantly reduced waste stream (e.g. anyreagents and/or percentage of composition not impacting themicro-efficacy of the compositions). Instead the present inventionprovides increased amounts of post-reaction products (e.g. performicacids) with decreased amounts of unreacted reagents.

In an aspect of the invention, a premix formulation may deliver theformic acid source and the oxidizing agent.

Suitable dispersing agents for use according to the concentrated premixformulations of the invention include polymers, surface active agents orany compounds which will help to achieve a meta-stable solution afterthe ester perhydrolysis through the interaction with the peroxy fattyacids generated through perhydrolysis. These may include, for example,sulfonated oleic acids (SOA), 1-octanesulfonic acid (NAS), sodium laurylsulfonates (SLS) and the like. In another aspect a premix formulationincludes an ester of a polyhydric alcohol and a carboxylic acid, anoxidizing agent and a solvent. Ethanol and methanol are examples ofsuitable solvents for use in stabilizing the concentrated premixformulation according to the invention. The use of the solvent incertain embodiments obviates the use of a dispersing agent for premixstability. However, in alternative embodiments a premix formulation mayinclude an ester of a polyhydric alcohol and a carboxylic acid, anoxidizing agent, a dispersing agent and a solvent. Without wishing to belimited to a particular theory or mechanism of action of the invention,the combined use of a dispersing agent and a solvent within aconcentrated premix formulation reduces the overall need for asurfactant dispersing agent in the premix composition.

Reaction Mixture Formation

According to an embodiment of the invention, the formic acid source andan oxidizing agent are combined to form a reaction mixture. In anembodiment of the invention, the formic acid source and an oxidizingagent are provided to the length of pipe. In an embodiment of theinvention, the formic acid source and oxidizing agent are provided to avessel located upstream of the inlet to the length of pipe andsubsequently provided to the length of pipe. According to theembodiments of the invention, flow direction through the system may beupward, downward, or lateral. However, as one skilled in the art wouldappreciate, flow direction may be dependent on the process and streamvariable such as density, temperature, and pressure, as well as externalmechanical considerations such as pumping power. In a preferredembodiment of the invention the second inlet which doses oxidizing agentto the system has a downward flow. In a further aspect of the invention,the reaction mixture is not formed by a mechanical means of mixing. Inan alternative embodiment of the invention, the reaction mixture isformed by a mechanical means of mixing, for example, such as animpeller, or the like as one skilled in the art will appreciate, forcirculation within the reaction vessel, circulation pumps or begravity-driven, employ additional holding vessels, reagent deliverysensors (e.g. proof of reagent and/or performic acid chemistry deliverysensor) or combinations of the same to meet the performic acid reactionkinetics of the system.

In an aspect of the invention, the timing of the reaction is dependenton the flow rate and/or flow direction of the reagents, the amount ofheat transfer available, and the desired concentration of performicacid. Although not intending to be limited by a particular theory of theinvention, the kinetics of the reaction according to the invention arepH, concentration, flow rate, and/or temperature dependent, and thereaction begins producing yield in the order of seconds to minutes. Insome aspects of the invention, the reaction can produce at least about2% performic acid instantaneously, at least about 4% formic acid withinabout 1 minute, and at least about 8% performic acid within about 2minutes. In a preferred embodiment of the invention, the duration of thereaction is preferably less than about 1 hour, preferably less thanabout 30 minutes, preferably less than about 15 minutes, and preferablyless than about 10 minutes. In a further aspect of the invention, thereaction is ran until completion, however as one skilled in the art canappreciate that there may be situations in which it may be desirable notto run the reaction to completion.

Heating of Reaction Mixture

In an aspect of the invention, the reaction mixture is heated within alength of pipe in order to effectuate the conversion of reagents toperformic acid. In some aspects of the invention, the reaction occurswithin a length of pipe which meets the hydraulic requirements of theperformic acid reaction kinetics. Although not intending to be limitedby a particular theory of the invention, the kinetics of the reactionaccording to the invention are pH, concentration, flow rate, and/ortemperature dependent, and the reaction can reach maximum yield in theorder of seconds to minutes. Although not intending to be limited by aparticular theory of the invention, the kinetics of the reactionaccording to the invention are pH, concentration, flow rate, and/ortemperature dependent, and the reaction begins producing yield in theorder of seconds to minutes. In some aspects of the invention, thereaction can produce at least about 2% performic acid instantaneously,at least about 4% formic acid within about 1 minute, and at least about8% performic acid within about 2 minutes. In some aspects the reactioncan reach maximum yield within about 15 seconds, or within about 30seconds, within about 1 minute, or within about 2 to about 5 minutes.The length of pipe may be designed in a variety of ways, including forexample shape, size, temperature, and material. According to anembodiment of the invention, the length of pipe may be of a given innerdiameter and is constructed of a material that is not readily corrodedand/or damaged by the presence of formic acid, hydrogen peroxide, and/orperformic acid(s). Such piping materials to be avoided include, forexample copper, chromium, brass, and/or iron. Certain varieties ofstainless steel are also to be avoided, for example, SS304. In apreferred embodiment of the invention, the length of pipe is constructedfrom SS316 and/or SS316L. However, one skilled in the art willappreciate that other suitable materials are available.

In some aspects of the invention, the length of pipe is limited bypressure of the system. For example, the pipe may be designed toaccommodate the potential occurrence of a runaway reaction. Preferablythe pipe is designed to accommodate pressures of at least 20 PSI, atleast 40 PSI, at least 50 PSI, at least 100 PSI, at least 150 PSI, atleast 500 PSI, at least 1000 PSI, or greater, including all rangestherein. In an aspect, as one skilled in the art will ascertain, thepressure of the system is controlled so as not to exceed the burstpressure of any material employed for the length of pipe of thegenerator or apparatus of the invention. Beneficially, additionalcomponents of the generator or apparatus may optionally include pressurerelief valves, rupture disks, or the like to control the pressure of thesystem.

In some aspects of the invention, the flow through the pipe occurs at arate of about 1 mL/minute to about 100 mL/min, preferably about 10mL/min to about 50 mL/min, preferably about 20 mL/min to about 40mL/min. In an aspect of the invention, higher flow rates can be achievedby employing the apparatuses in parallel. In an aspect of the invention,it is preferred that flow through the pipe has a laminar flow pattern,i.e., flow have a Reynolds number of less than about 2040 in order toallow for uniform heating.

In an aspect of the invention, heat is provided to the system throughthe use of a cartridge, heat exchanger, steam jacket, steam preheat, anelectrical source, a heat wrap or combinations thereof, which may bereferred to herein as heating device. In some aspects of invention, thelocation of the heating device within the section of pipe is furtherwrapped in insulation to eliminate the amount of heat lost to theenvironment.

In a preferred embodiment of the system, heat is provided to the systemin an amount sufficient to raise the temperature of the reagents toaccelerate the reaction and to a temperature not exceeding thedecomposition temperature of performic acid, or about 200° C. Morepreferably, heat is provided to the system in an amount sufficient toraise the temperature of the reagents to a temperature not exceeding180° C. In an aspect, the temperature increase will increase the rate ofreaction, however, as one skilled in the art will ascertain, thestability of the performic acid is not to be compromised by increasingthe temperature, including at a temperature not exceeding 200° C.

In a further aspect of the invention, a uniform heating of the reagentswithin the length of pipe is desired, such uniform heating is influencedby the radial distance from the outside of the heater surface to theinner surface of the pipe, where a larger distance leads to a highergradient, and the length of the heating zone, where longer contact withheater leads to a lower gradient. As one skilled in the art willappreciate, these influences have inverse effects on the heat gradientand will thus appreciate the weighing of these influences whendetermining the dimensions of the heating devices. In an alternativeaspect, a staged heating of reagents within the length of pipe isdesired.

In some aspects of the present invention, wherein the heating device isa cartridge, the available volume of the pipe is affected. The availablevolume is thus defined as the volume held within the pipe at a giventime minus the volume occupied by the heating cartridge. In a preferredembodiment, the volume of the system is increased by employing systemsin parallel rather than increasing pipe size and or volume.

In some aspects of the invention, the power required by the heatingdevice and accompanying pumps preferably does not exceed about 100 wattsfor flow rates of 50 mL/min. More preferably, the power does not exceed80 watts and more preferably, the power does not exceed 50 watts.

Performic Acid Delivery

In a preferred aspect of the present invention, the performic acid isdelivered to a downstream process via an outlet. In an aspect of theinvention the outlet provides the performic acid chemistries to adownstream process as desired by the controller and/or user. In anaspect, the outlet provides the performic acid chemistries to a storagereservoir. In an aspect, the outlet provides the performic acidchemistries to a cooling system. In an aspect of the invention, theconcentration of the performic acid at the outlet is at least 1 wt-%,more preferably at least 5 wt-% at the outlet.

Cooling of Performic Acid

In a further aspect of the invention, the performic acid is cooled via acooling loop/segment. Such a cooling system may be in combination with asafety mechanism and/or a measurement device of the system. It may bedesirable to have components of the system under temperature controls.As one skilled in the art will appreciate, exothermic reactions maydegrade the reagents according to the generation of the performic acidcompositions of the invention. In an aspect, the cooling systemstabilizes the performic acid composition and thereby increasesshelf-life by lowering the temperature to a temperature to that offreezing or below freezing. In addition, according to an embodiment ofthe invention, the system has at least one mechanism to cool componentsof the system. Multiple cooling mechanisms may be used in either seriesor parallel. Such mechanisms may include, for example, a quenching mode,increased surface area, cooling jacket, venting systems, cold finger,and the like. In a further aspect of the invention, the outlet of theperformic acid(s) is cooled by using heat exchange, refrigerationsleeve, blower, cooled vessel, etc.

Measurement Devices

In a further aspect of the invention, the methods according to thepresent invention for producing performic acid forming compositions orperformic acid compositions include measuring at least one value or aplurality of values. Such measuring is accomplished by the use ofmeasurement devices. Such measurement devices are those suitable tomeasure one or more reaction kinetics or system operations for thegeneration of performic acid forming compositions, including for exampledevices to measure conductivity, weight, flow (e.g. flow meters orswitches), pH, pressure, temperature and combinations thereof. Suchmeasurement devices may measure the system's inlets, piping, outlets,etc.

Examples of additional suitable measurement devices include conductivitysensors, thermometers, out of product alarms, peroxide monitors,IR/UV/VIS spectroscopy and pressure switches. For example, in anembodiment of the invention, temperature is monitored a various pointsin the apparatus to ensure consistent heating at a temperature notexceeding the flash point of the performic acid. Additionally, in anembodiment of the invention pressure is monitors to ensure there is notan occurrence of a “runaway reaction.” This pressure monitoring could beaccomplished by use of a differential pressure sensor within a feedbackcontrol loop, wherein in a pressure reading exceeding a set point wouldcause a safety release valve to be employed or venting to occur. In afurther embodiment of the invention, flow rate is monitored with eithera pressure sensor or an orifice plate/meter. Furthermore, conductivitymay be monitored to determine the concentration of products in thestream and/or the concentration of the performic acid at the outlet. Ina further embodiment, generation rates, temperatures, and concentrationscan all be optimized via monitoring systems and/or controllers.Additionally, an embodiment of the invention would allow for rinsing ofthe apparatus so that residual chemistry does not remain in the system.Still further examples of suitable measurement devices are disclosedherein, in addition various embodiments of those disclosed in U.S.patent application Ser. No. 12/108,202, and U.S. Pat. No. 7,547,421,both entitled Apparatus and Method for Making Peroxycarboxylic Acid,which are herein incorporated by reference in their entirety.

Control System

In a further aspect of the invention, the methods according to thepresent invention for producing performic acid forming compositions orperformic acid compositions includes controlling the method by use of anoptional controller or software platform. The software platform providesa user or system to select a generation mode for a desired performicacid formulation for on-site generation. As a result, use of the systemfor on-site performic acid chemistry generation provides significantuser flexibility to generate chemistries for particular user-identifiedpurposes. For example, the controller or control software for operationof the system may permit a user or system to select both the performicacid formulation and the desired volume of the formulation for on-sitegeneration. In a further aspect, the control software may determine thetiming, sequencing and/or selection of feeding raw materials (e.g.reagents) into the system, mixing time and total reaction time requiredfor production of the user- or system-selected performic acidformulation. In a still further aspect of the invention, the controlsystem includes the above described measurement devices.

According to the invention, the controller may further include amechanism for manually starting/stopping any of the same functions,including for example a manual switch panel for the same. In addition tomanual controls, such as a manual switch panel, the controllerpreferably has buttons or other means for selecting particularembodiments according to option displayed by the control softwareplatform. An embodiment of the controller may further include a displayscreen to assist a user in selecting a generation mode for a desiredperformic acid formulation and any other options for user selection asone skilled in the art will ascertain based upon the description of theinvention. Concomitant with the control software are user-friendlyinstructions for use displayed on the display screen (or the like).

In an aspect of the invention, the control software utilizes a controlsoftware algorithm to maximize on-site active chemistry yield andprovide safe operating conditions for the reactor vessel(s) of thesystem. The control software permits user-identified chemistryproduction to be run in one or multiple reaction vessels and to properlysequence reactions to obtain active chemistries.

Examples of suitable controllers are disclosed herein, in additionvarious embodiments of those disclosed in U.S. patent application Ser.No. 12/108,202, and U.S. Pat. No. 7,547,421, both entitled Apparatus andMethod for Making Peroxycarboxylic Acid, which are herein incorporatedby reference in their entirety.

In another aspect of the invention, the system may include a data outputmeans for sharing information related to the performic acid formingcompositions and/or performic acid formulations generated according tothe system. For example, an information backbone may be used to bothcollect and disseminate data from the process of generating theperformic acid formulations including, for example, compositionconsumption, dispensing or usage, and additional formulationproduction-related data. Such data may be generated in real-time and/orprovided in a historical log of operational data detectable or storableby a user or system. In an embodiment of the invention a user or systemis able to monitor usage and performance, including for example,chemistry dispensing, managing chemistry distribution to variouspoint-of-use applications, communication with system operators tocontrol and monitor chemistry dispensing, allocation and/or formulationand the like. According to an additional embodiment of the invention, auser or system is able to control systems, including program systems,remotely.

According to an aspect of the invention, any system operations suitablefor use with the invention may be controlled and/or monitored from aremote location. Remote system operations control and/or monitoring mayfurther include the system updates and/or upgrades. According to anaspect of the invention updates and/or upgrades to system operations maybe downloaded remotely. These and other embodiments of data outputmeans, information sharing, remote system operations and the like, whichmay be adapted for use with the present invention, are furtherdescribed, for example, in U.S. Pat. Nos. 7,292,917, 6,895,307,6,697,706 and 6,377,868 and U.S. Patent Publication Nos. 2005/0102059,2005/0065644, 2004/0088076, 2003/0195657 and 2003/0195656, which arehereby expressly incorporated by reference including, withoutlimitation, the specification, claims, and abstract, as well as anyfigures, tables, or drawings thereof.

In another aspect of the invention, the data output for sharinginformation related to the compositions according to the system maycoordinate multiple systems on at a single site. According to thisembodiment of the invention, information sharing between the multiplesystems may take places place using any communications network capableof coupling one or more systems according to the present invention,including for example, using a server computer and a database.

Safety Devices

In a further aspect of the invention, the methods according to thepresent invention for producing performic acid forming compositions orperformic acid composition include employing safety devices. Exemplaryon-site safety feedback mechanisms for a system are disclosed in furtherdetail in U.S. Patent Publication No. 2009/0208365, which is herebyexpressly incorporated by reference including, without limitation, thespecification, claims, and abstract, as well as any figures, tables, ordrawings thereof. Various safety mechanisms can measure pressure,temperature, difference in pressure, difference in temperature, or acombination thereof and provide a perceptible signal if one or more ofthese increases above a predetermined level. In an aspect, the level ofpressure, temperature, difference in pressure, difference intemperature, or a combination thereof at which safety system provides aperceptible signal can be selected to allow intervention to avoidundesirable or unsafe conditions. In a further aspect of the invention,the system is designed to accommodate at least 5 times the pressure ofthe system (i.e. design pressure), more preferably at least 3 times thepressure of the system, and more preferably at least 1.5-2 times thepressure of the system. In a further aspect, the system is designed forexplosion safety ratings, such as for example, according to the AmericanPetroleum Institute (API). In a further aspect of the invention, thesystem may include pressure relief valves and/or rupture discs.

Methods Employing Performic Acid Compositions

In some aspects, the present disclosure includes methods of using theperformic acid forming compositions disclosed herein. In some aspects,the methods of using the compositions employ a chemistry having a pH offrom about 0 to about 5 for various antimicrobial and/or bleachingapplications. In other aspects, the methods of using the compositionsemploy a chemistry having a pH of from about 5 to about 9 for variousantimicrobial and/or bleaching applications. In still further aspects,the methods of using the compositions employ a chemistry having a pH offrom about 5 to about 14 for various bleaching applications.

In some aspects, the present disclosure includes methods of using theperformic acid forming compositions and/or performic acids disclosedherein. Performic acid compositions generated according to theembodiments of the invention may be used for a variety ofuser-identified biocidal and/or anti-microbial purposes. In someaspects, the on-site generated performic acid compositions may beemployed for antimicrobial and/or bleaching methods of use. In furtheraspects, the on-site generated performic acid compositions may beemployed for any sanitizing methods of use. For example, the inventionincludes a method for reducing a microbial population, a method forreducing the population of a microorganism on skin, a method fortreating a disease of skin, a method for reducing an odor, or a methodfor bleaching. These methods can operate on an object, surface, in abody or stream of water or a gas, or the like, by contacting the object,surface, body, or stream with a performic acid composition of theinvention. Contacting can include any of numerous methods for applying acomposition, such as spraying the composition, immersing the object inthe composition, foam or gel treating the object with the composition,wiping the composition or a combination thereof

In some aspects, a composition obtained according to the methods andapparatus of the present invention includes an amount of a performicacid composition of the present invention effective for killing one ormore of the food-borne pathogenic bacteria associated with a foodproduct, including, but not limited to, Salmonella typhimurium,Salmonellajaviana, Campylobacterjejuni, Listeria monocytogenes, andEscherichia coli O157:H7, yeast, and mold. In some embodiments, thecompositions obtained according to the methods and apparatus of thepresent invention include an amount of a performic acid compositioneffective for killing one or more of the pathogenic bacteria associatedwith a health care surfaces and environments including, but not limitedto, Salmonella typhimurium, Staphylococcus aureus, Salmonellacholeraesurus, Pseudomonas aeruginosa, Escherichia coli, mycobacteria,yeast, and mold. The compositions obtained according to the methods andapparatus of the present invention have activity against a wide varietyof microorganisms such as Gram positive (for example, Listeriamonocytogenes or Staphylococcus aureus) and Gram negative (for example,Escherichia coli or Pseudomonas aeruginosa) bacteria, yeast, molds,bacterial spores, viruses, etc. The compositions obtained according tothe methods and apparatus of the present invention, as described above,have activity against a wide variety of human pathogens. The presentcompositions obtained according to the methods and apparatus of thepresent invention can kill a wide variety of microorganisms on a foodprocessing surface, on the surface of a food product, in water used forwashing or processing of food product, on a health care surface, in ahealth care environment or the like.

The compositions obtained according to the methods and apparatus of theinvention can be used for a variety of domestic or industrialapplications, e.g., to reduce microbial or viral populations on asurface or object or in a body or stream of water. The compositions canbe applied in a variety of areas including kitchens, bathrooms,factories, hospitals, dental offices, restaurants, clean in placeapplications, laundry or textile applications and food plants, and canbe applied to a variety of hard or soft surfaces having smooth,irregular or porous topography. Suitable hard surfaces include, forexample, architectural surfaces (e.g., floors, walls, windows, sinks,tables, counters and signs); eating utensils; hard-surface medical orsurgical instruments and devices; and hard-surface packaging. Such hardsurfaces can be made from a variety of materials including, for example,ceramic, metal, glass, wood or hard plastic.

Suitable soft surfaces include, for example, paper; filter media,hospital and surgical linens and garments; soft-surface medical orsurgical instruments and devices; and soft-surface packaging. Such softsurfaces can be made from a variety of materials including, for example,paper, fiber, woven or nonwoven fabric, soft plastics and elastomers.The compositions obtained according to the methods and apparatus of theinvention can also be applied to soft surfaces such as food and skin(e.g., a hand). The present compositions can be employed as a foaming ornonfoaming environmental sanitizer or disinfectant.

The performic acid compositions obtained according to the methods andsystem of the present invention can be included in products such assterilants, sanitizers, disinfectants, preservatives, deodorizers,antiseptics, fungicides, germicides, sporicides, virucides, detergents,bleaches, hard surface cleaners, hand soaps, waterless hand sanitizers,and pre- or post-surgical scrubs.

The compositions can also be used in veterinary products such asmammalian skin treatments or in products for sanitizing or disinfectinganimal enclosures, pens, watering stations, and veterinary treatmentareas such as inspection tables and operation rooms. The presentcompositions can be employed in an antimicrobial foot bath for livestockor people. The compositions can also be employed as an antimicrobialteat dip.

In some aspects, the compositions obtained according to the methods andapparatus of the present invention can be employed for reducing thepopulation of pathogenic microorganisms, such as pathogens of humans,animals, and the like. As one skilled in the art will ascertain, thereducing of pathogenic microorganism populations is particularlysuitable for healthcare and institutional applications of use. Thecompositions exhibit activity against pathogens including fungi, molds,bacteria, spores, and viruses, for example, S. aureus, E. coli,Streptococci, Legionella, Pseudomonas aeruginosa, mycobacteria,tuberculosis, phages, or the like. Such pathogens can cause a variety ofdiseases and disorders, including mastitis or other mammalian milkingdiseases, tuberculosis, and the like. The compositions of the presentinvention can reduce the population of microorganisms on skin or otherexternal or mucosal surfaces of an animal. In addition, the presentcompositions can kill pathogenic microorganisms that spread throughtransfer by water, air, or a surface substrate. The composition needonly be applied to the skin, other external or mucosal surfaces of ananimal water, air, or surface.

The performic acid compositions obtained according to the methods andapparatus of the present invention can also be used on foods and plantspecies to reduce surface microbial populations; used at manufacturingor processing sites handling such foods and plant species; or used totreat process waters around such sites. For example, the compositionscan be used on food transport lines (e.g., as belt sprays); boot andhand-wash dip-pans; food storage facilities; anti-spoilage aircirculation systems; refrigeration and cooler equipment; beveragechillers and warmers, blanchers, cutting boards, third sink areas, andmeat chillers or scalding devices. The compositions of the invention canbe used to treat produce transport waters such as those found in flumes,pipe transports, cutters, slicers, blanchers, retort systems, washers,and the like. Particular foodstuffs that can be treated withcompositions of the invention include, but are not limited to, eggs,meats, seeds, leaves, fruits and vegetables. Particular plant surfacesinclude both harvested and growing leaves, roots, seeds, skins orshells, stems, stalks, tubers, corms, fruit, and the like. Thecompositions may also be used to treat animal carcasses to reduce bothpathogenic and non-pathogenic microbial levels.

The compositions can also be used to treat waste water where both itsantimicrobial function and its oxidant properties can be utilized. Asidefrom the microbial issues surrounding waste water, it is often rich inmalodorous compounds of reduced sulfur, nitrogen or phosphorous. Astrong oxidant such as the present invention converts these compoundsefficiently to their odor free derivatives e.g. the sulfates, phosphatesand amine oxides. These same properties are very useful in the pulp andpaper industry where the property of bleaching is also of great utility.

In some aspects, the compositions obtained according to the methods andapparatus of the present invention are useful in the cleaning orsanitizing of containers, processing facilities, or equipment in thefood service or food processing industries. The compositions haveparticular value for use on food packaging materials and equipment, andespecially for cold or hot aseptic packaging. Examples of processfacilities in which the composition of the invention can be employedinclude a milk line dairy, a continuous brewing system, food processinglines such as pumpable food systems and beverage lines, etc. Foodservice wares can be treated with an antimicrobial and/or disinfectedwith the composition of the invention. For example, the compositions canalso be used on or in ware wash machines, dishware, bottle washers,bottle chillers, warmers, third sink washers, cutting areas (e.g., waterknives, slicers, cutters and saws), egg washers or the like. Particulartreatable surfaces include, but are not limited to, packaging such ascartons, bottles, films and resins; dish ware such as glasses, plates,utensils, pots and pans; ware wash machines; exposed food preparationarea surfaces such as sinks, counters, tables, floors and walls;processing equipment such as tanks, vats, lines, pumps and hoses (e.g.,dairy processing equipment for processing milk, cheese, ice cream andother dairy products); and transportation vehicles. Containers includeglass bottles, PVC or polyolefin film sacks, cans, polyester, PEN or PETbottles of various volumes (100 ml to 2 liter, etc.), one gallon milkcontainers, paper board juice or milk containers, etc.

The compositions can also be used on or in other industrial equipmentand in other industrial process streams such as heaters, cooling towers,boilers, retort waters, rinse waters, aseptic packaging wash waters, andthe like. The compositions can be used to treat microbes and odors inrecreational waters such as in pools, spas, recreational flumes andwater slides, fountains, and the like. The composition can also be usedin treating microbes found in aqueous systems associated with petroleumor LP gas recovery or fermentation processes and pulp and paperprocesses and the like.

A filter containing performic acid compositions of the present inventioncan reduce the population of microorganisms in air and liquids. Such afilter can remove water and air-borne pathogens such as Legionella.

The compositions obtained according to the methods and apparatus of thepresent invention can be employed for reducing the population ofmicrobes, fruit flies, or other insect larva on a drain or othersurface.

The compositions of the present invention can also be employed bydipping food processing equipment into the use solution, soaking theequipment for a time sufficient to sanitize or de-stain the equipment,and wiping or draining excess solution off the equipment. Thecompositions of the present invention may be further employed byspraying or wiping food processing surfaces with the use solution,keeping the surfaces wet for a time sufficient to sanitize the surfaces,and removing excess solution by wiping, draining vertically, vacuuming,etc.

The compositions obtained according to the methods and system of thepresent invention may also be used in a method of sanitizing hardsurfaces such as institutional type equipment, utensils, dishes, healthcare equipment or tools, and other hard surfaces.

The compositions of the present invention can also be used for laundryor textile applications. The compositions can be employed by rinsinglaundry or textile surfaces with the use solution, keeping the surfaceswet for a sufficient time to wash, de-stain, sanitize, bleach and/orrinse the surface.

The performic acid compositions can be applied to microbes or to soiledor cleaned surfaces using a variety of methods. These methods canoperate on an object, surface, in a body or stream of water or a gas, orthe like, by contacting the object, surface, body, or stream with acomposition of the invention. Contacting can include any of numerousmethods for applying a composition, such as spraying the composition,immersing the object in the composition, rinsing the composition, foamor gel treating the object with the composition, applying with a wipesystem or a combination thereof.

A concentrate or use concentration of a performic acid compositionobtained according to the methods and apparatus of the present inventioncan be applied to or brought into contact with an object by anyconventional method or apparatus for applying an antimicrobial orcleaning composition to an object. For example, the object can be wipedwith, sprayed with, foamed on, and/or immersed in the composition, or ause solution made from the composition. The compositions can be sprayed,foamed, or wiped onto a surface; the composition can be caused to flowover the surface, or the surface can be dipped into the composition.Contacting can be manual or by machine. Food processing surfaces, foodproducts, food processing or transport waters, and the like can betreated with liquid, foam, gel, aerosol, gas, wax, solid, or powderedperformic acid compositions according to the invention, or solutionscontaining these compositions.

Other hard surface cleaning applications for the compositions includeclean-in-place systems (CIP), clean-out-of-place systems (COP),washer-decontaminators, sterilizers, textile laundry machines, ultra andnano-filtration systems and indoor air filters. COP systems can includereadily accessible systems including wash tanks, soaking vessels, mopbuckets, holding tanks, scrub sinks, vehicle parts washers,non-continuous batch washers and systems, and the like. CIP systemsinclude the internal components of tanks, lines, pumps and other processequipment used for processing typically liquid product streams such asbeverages, milk, juices.

A method of sanitizing substantially fixed in-place process facilitiesincludes the following steps. A composition in accordance with variousembodiments of the invention is introduced into the process facilitiesat a temperature in the range of about 4° C. to 60° C. Afterintroduction of the composition, the solution is held in a container orcirculated throughout the system for a time sufficient to sanitize theprocess facilities (e.g., to kill undesirable microorganisms). After thesurfaces have been sanitized by means of the present compositions, thesolution is drained. Upon completion of the sanitizing step, the systemoptionally may be rinsed with other materials such as potable water. Thecompositions can be circulated through the process facilities for 10minutes or less.

The present methods can include delivering the present composition viaair delivery to the clean-in-place or other surfaces such as thoseinside pipes and tanks. This method of air delivery can reduce thevolume of solution required.

Methods for Contacting a Food Product

In some aspects, the present invention provides methods for contacting afood product with compositions according to the invention employing anymethod or apparatus suitable for applying such compositions. Forexample, in some embodiments, the food product is contacted by thecompositions with a spray of the compositions, by immersion in thecompositions, by foam or gel treating with the compositions. Contactwith a spray, a foam, a gel, or by immersion can be accomplished by avariety of methods known to those of skill in the art for applyingantimicrobial agents to food. Contacting the food product can occur inany location in which the food product might be found, such as field,processing site or plant, vehicle, warehouse, store, restaurant, orhome. These same methods can also be adapted to apply the compositionsof the present invention to other objects.

The present methods require a certain minimal contact time of thecompositions with food product for occurrence of significantantimicrobial effect. The contact time can vary with concentration ofthe use compositions, method of applying the use compositions,temperature of the use compositions, amount of soil on the food product,number of microorganisms on the food product, type of antimicrobialagent, or the like. The exposure time can be at least about 5 to about15 seconds. In some embodiments, the exposure time is about 15 to about30 seconds. In other embodiments, the exposure time is at least about 30seconds.

In some embodiments, the method for washing a food product employs apressure spray including compositions of the present invention. Duringapplication of the spray solution on the food product, the surface ofthe food product can be moved with mechanical action, e.g., agitated,rubbed, brushed, etc. Agitation can be by physical scrubbing of the foodproduct, through the action of the spray solution under pressure,through sonication, or by other methods. Agitation increases theefficacy of the spray solution in killing micro-organisms, perhaps dueto better exposure of the solution into the crevasses or small coloniescontaining the micro-organisms. The spray solution, before application,can also be heated to a temperature of about 15 to 20° C., for example,about 20 to 60° C. to increase efficacy. The spray stabilizedcompositions can be left on the food product for a sufficient amount oftime to suitably reduce the population of microorganisms, and thenrinsed, drained, or evaporated off the food product. Application of thematerial by spray can be accomplished using a manual spray wandapplication, an automatic spray of food product moving along aproduction line using multiple spray heads to ensure complete contact,or other spray apparatus. One automatic spray application involves theuse of a spray booth. The spray booth substantially confines the sprayedcompositions to within the booth. The production line moves the foodproduct through the entryway into the spray booth in which the foodproduct is sprayed on all its exterior surfaces with sprays within thebooth. After a complete coverage of the material and drainage of thematerial from the food product within the booth, the food product canthen exit the booth. The spray booth can include steam jets that can beused to apply the stabilized compounds of the invention. These steamjets can be used in combination with cooling water to ensure that thetreatment reaching the food product surface is less than 65° C., e.g.,less than 60° C. The temperature of the spray on the food product isimportant to ensure that the food product is not substantially altered(cooked) by the temperature of the spray. The spray pattern can bevirtually any useful spray pattern.

Immersing a food product in the liquid compositions of the presentinvention can be accomplished by any of a variety of methods known tothose of skill in the art. For example, the food product can be placedinto a tank or bath containing the compositions. Alternatively, the foodproduct can be transported or processed in a flume of the compositions.The washing solution can be agitated to increase the efficacy of thesolution and the speed at which the solution reduces micro-organismsaccompanying the food product. Agitation can be obtained by conventionalmethods, including ultrasonics, aeration by bubbling air through thesolution, by mechanical methods, such as strainers, paddles, brushes,pump driven liquid jets, or by combinations of these methods. Thewashing solution can be heated to increase the efficacy of the solutionin killing micro-organisms. After the food product has been immersed fora time sufficient for the desired antimicrobial effect, the food productcan be removed from the bath or flume and the compositions can berinsed, drained, or evaporated off the food product.

In other embodiments, a food product can be treated with a foamingversion of the compositions of the present invention. The foam can beprepared by mixing foaming surfactants with the washing solution at timeof use. The foaming surfactants can be nonionic, anionic or cationic innature. Examples of useful surfactant types include, but are not limitedto the following: alcohol ethoxylates, alcohol ethoxylate carboxylate,amine oxides, alkyl sulfates, alkyl ether sulfate, sulfonates,including, for example, alkyl aryl sulfonates, quaternary ammoniumcompounds, alkyl sarcosines, betaines and alkyl amides. The foamingsurfactant is typically mixed at time of use with the washing solution.Use solution levels of the foaming agents is from about 50 ppm to about2.0 wt-%. At time of use, compressed air can be injected into themixture, then applied to the food product surface through a foamapplication device such as a tank foamer or an aspirated wall mountedfoamer.

In some embodiments, a food product can be treated with a thickened orgelled version of the compositions of the present invention. In thethickened or gelled state the washing solution remains in contact withthe food product surface for longer periods of time, thus increasing theantimicrobial efficacy. The thickened or gelled solution will alsoadhere to vertical surfaces. The compositions can be thickened or gelledusing existing technologies such as: xanthan gum, polymeric thickeners,cellulose thickeners, or the like. Rod micelle forming systems such asamine oxides and anionic counter ions could also be used. The thickenersor gel forming agents can be used either in the concentrated product ormixing with the washing solution, at time of use. Typical use levels ofthickeners or gel agents range from about 100 ppm to about 10 wt-%.

Methods for Beverage, Food, and Pharmaceutical Processing

The compositions of the present invention can be used in the manufactureof beverage, food, and pharmaceutical materials including fruit juice,dairy products, malt beverages, soybean-based products, yogurts, babyfoods, bottled water products, teas, cough medicines, drugs, and softdrinks. The compositions of the present invention can be used tosanitize, disinfect, act as a sporicide for, or sterilize bottles,pumps, lines, tanks and mixing equipment used in the manufacture of suchbeverages. Further, the compositions of the present invention can beused in aseptic, cold filling operations in which the interior of thefood, beverage, or pharmaceutical container is sanitized or sterilizedprior to filling. In such operations, a container can be contacted withthe compositions, typically using a spray, dipping, or filling device tointimately contact the inside of the container with the compositions,for a sufficient period of time to reduce microorganism populationswithin the container. The container can then be emptied of the amount ofsanitizer or sterilant used. After emptying, the container can be rinsedwith potable water or sterilized water and again emptied. After rinsing,the container can be filled with the beverage, food, or pharmaceutical.The container can then be sealed, capped or closed and then packed forshipment for ultimate sale. The sealed container can be autoclaved orretorted for added microorganism kill.

In food, beverage, or pharmaceutical manufacturing, fungalmicroorganisms of the genus Chaetomium or Arthrinium, and spores orbacteria of the genus Bacillus spp. can be a significant problem inbottling processes, particularly in cold aseptic bottling processes. Thecompositions of the present invention can be used for the purpose ofcontrolling or substantially reducing (by more than a 5 log₁₀ reduction)the number of Chaetomium or Arthrinium or Bacillus microorganisms inbeverage or food or pharmaceutical bottling lines using cold asepticbottling techniques.

In such techniques, metallic, aluminum or steel cans can be filled,glass bottles or containers can be filled, or plastic (PET or PBT orPEN) bottles, and the like can be filled using cold aseptic fillingtechniques. In such processes, the compositions of the invention can beused to sanitize the interior of beverage containers prior to fillingwith the carbonated (or noncarbonated) beverage. Typical carbonatedbeverages in this application include, but are not limited to, colabeverages, fruit beverages, ginger ale beverages, root beer beverages,iced tea beverages which may be non-carbonated, and other commonbeverages considered soft drinks. The compositions of the invention canbe used to sanitize both the tanks, lines, pumps, and other equipmentused for the manufacture and storage of the soft drink material and alsoused in the bottling or containers for the beverages. In an embodiment,the compositions are useful for killing both bacterial and fungalmicroorganisms that can be present on the surfaces of the productionequipment and beverage containers.

Methods for Industrial Processing

In some aspects, the invention includes methods of using the performicacid forming compositions and/or performic acids to prevent biologicalfouling in various industrial processes and industries, including oiland gas operations, to control microorganism growth, eliminate microbialcontamination, limit or prevent biological fouling in liquid systems,process waters or on the surfaces of equipment that come in contact withsuch liquid systems. As referred to herein, microbial contamination canoccur in various industrial liquid systems including, but not limitedto, air-borne contamination, water make-up, process leaks and improperlycleaned equipment. In another aspect, the performic acid formingcompositions and/or performic acids are used to control the growth ofmicroorganisms in water used in various oil and gas operations. In afurther aspect, the compositions are suitable for incorporating intofracturing fluids to control or eliminate microorganisms.

For the various industrial processes disclosed herein, “liquid system”refers to flood waters or an environment within at least one artificialartifact, containing a substantial amount of liquid that is capable ofundergoing biological fouling, it includes but is not limited toindustrial liquid systems, industrial water systems, liquid processstreams, industrial liquid process streams, industrial process watersystems, process water applications, process waters, utility waters,water used in manufacturing, water used in industrial services, aqueousliquid streams, liquid streams containing two or more liquid phases, andany combination thereof.

In at least one embodiment this technology would be applicable to anyprocess or utility liquid system where microorganisms are known to growand are an issue, and biocides are added. Examples of some industrialprocess water systems where the method of this invention could beapplied are in process water applications (flume water, shower water,washers, thermal processing waters, brewing, fermentation, CIP (clean inplace), hard surface sanitization, etc.), Ethanol/Bio-fuels processwaters, pretreatment and utility waters (membrane systems, ion-exchangebeds), water used in the process/manufacture of paper, ceiling tiles,fiber board, microelectronics, E-coat or electro depositionapplications, process cleaning, oil exploration and energy services(completion and work over fluids, drilling additive fluids, fracturingfluids, flood waters, etc.; oil fields—oil and gas wells/flow line,water systems, gas systems, etc.), and in particular water systems wherethe installed process equipment exhibits lowered compatibility tohalogenated biocides.

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, numerous equivalents to thespecific procedures, embodiments, claims, and examples described herein.Such equivalents are considered to be within the scope of this inventionand covered by the claims appended hereto. The contents of allreferences, patents, and patent applications cited throughout thisapplication are hereby incorporated by reference. The invention isfurther illustrated by the following examples, which should not beconstrued as further limiting.

All publications and patent applications in this specification areindicative of the level of ordinary skill in the art to which thisinvention pertains. All publications and patent applications are hereinincorporated by reference to the same extent as if each individualpublication or patent application was specifically and individuallyindicated by reference.

EXAMPLES

Embodiments of the present invention are further defined in thefollowing non-limiting Examples. It should be understood that theseExamples, while indicating certain embodiments of the invention, aregiven by way of illustration only. From the above discussion and theseExamples, one skilled in the art can ascertain the essentialcharacteristics of this invention, and without departing from the spiritand scope thereof, can make various changes and modifications of theembodiments of the invention to adapt it to various usages andconditions. Thus, various modifications of the embodiments of theinvention, in addition to those shown and described herein, will beapparent to those skilled in the art from the foregoing description.Such modifications are also intended to fall within the scope of theappended claims.

Equipment configuration and software were developed for on-sitegeneration of performic acid compositions, including performic acidforming compositions and performic acid for use as biocides. A reactormodule meeting the hydraulic requirements of the reaction kinetics wasdeveloped to obtain precise and repeatable generation of activeperformic acid chemistry. In addition, a software algorithm wasdeveloped to run one or multiple reactor modules to sequence eventsappropriately to maximize active yield and safely operate the reactormodule.

Example 1

An exemplary single reaction module was configured according to FIG. 2.In the single reaction module, performic acid were generated through theaddition of formic acid and hydrogen peroxide. A number of correlationswere developed, for example, FIGS. 5 and 6 illustrate the relationshipbetween fluid bulk temperature, cartridge heater skin temperature, andflow rate. The FIGS. were created using the SolidWorks ComputationalFluid Dynamics (CFD) package SolidWorks Flow. A simplified model was setup to analyze the heat transfer characteristics of the Formic acid flowinto the generator up to the Hydrogen Peroxide inlet. The model was setup using standard pipe sizes ½″, 1″, and 2″ using stainless steelmaterial properties. A ¼″ diameter cartridge heater 6″ long was insertedthrough a tee connector and into a 10″ long straight pipe section.Formic acid entered the computational domain at a tee mounted verticallyabove the cartridge via a 2.5″ pipe nipple of the appropriate diameterfor each simulation. Using this physical model, two inputs were used togenerate the range of data: inlet flow rate and heater power. Formicacid entering the computational domain was set to a flow rate of either20 or 40 mL/min. The cartridge heater was assumed to generate a uniformsurface flux at various power levels to generate the range of datapoints. For FIG. 5, the cartridge skin temperature reported was themaximum temperature found on any part of the cartridge surface. For bothfigures, the average outlet surface temperature was taken as an areaaverage of the fluid temperature across a plane normal to the flow atthe end of the 10 inch long pipe section.

According to FIG. 5, there is an approximately linear relationshipbetween the average outlet surface temperature and the skin temperatureof the cartridge. Additionally, FIG. 6 indicates that the heater powerdivided by the flow rate is linearly related to the average outletsurface fluid temperature.

Furthermore, FIG. 7 illustrates Heat Flow on a contour plot of Flow Ratevs. Inlet Temp. The depicted data comes from an equation that sets anoutlet temperature of 50° C. at the end of a heating element, andassumes all of the heat coming from the heating element in the performicacid generator is transferred into the fluid flowing past the heatingelement. This gives a minimum value for the amount of heat required. Thefigure shows the effect of reagent inlet temperature and heater power,in that the higher heater power is required for higher flow rates andlow reagent temperatures may lead to thermal decomposition of thereagent. Such a problem may be resolved by employing staged heatersand/or adjusting the size of the heating element.

Example 2

An exemplary single reaction module is configured according to FIG. 2.The control software maintained a set point temperature of 50° C. at thepoint of adding the peroxide source to the warm formic acid. A formicacid to peroxide premix formulation of 5.21:1 was used over a series oftitrations. An iodometric titration procedure is utilized. Approximately200 g of deionized ice water is added to an Erlenmeyer flask along withabout 0.30 to about 0.50 grams of sample. The final sample size isrecorded for later calculations. Approximately 2 mL of glacial aceticacid, 5 mL of 10% potassium iodine solution and 2 mL of starch is addedto the sample which is then placed on a stir plate and immediatelytitrated with 0.1 N sodium thiosulfate titrant to a colorless endpointthat persisted for at least 20 seconds. Volume of the titrant used isrecorded as titrant 1 for later calculations. To the same flask,approximately 3 mL of 9 N sulfuric acid and 2 mL ammonium molybdate,which is then allowed to rest in the sample for approximately 2 to 3minutes. The flask is then placed on a stir plate and immediatelytitrated with 0.1 N sodium thiosulfate titrant to a second colorlessendpoint that persists for at least 20 seconds. Volume of the titrantused is recorded as titrant 2 for later calculations. Table 1 indicatesthe results of the iodometric titration method and subsequentcalculations for measuring the performic acid and hydrogen peroxide.

TABLE 1 Titration Data % Performic Acid % Hydrogen Peroxide 5.48 0 5.300 5.57 0.21

Table 1 shows the ratio of performic acid to hydrogen peroxide generatedaccording to the in situ synthesis of performic acid in the apparatus ofthe invention.

Example 3

An exemplary single reaction module is configured according to FIG. 2. Aconductivity probe was used to take measurements of the reaction. Use ofa conductivity probe provides an electroanalytical method to measurevarious parameters of a product. An exemplary conductivity sensorscomprises two electrodes, and operates by applying a voltage across thetwo electrodes and measuring a resulting current. The relationshipbetween the magnitudes of the current and the voltage allow theresistance and therefore conductivity of the product to be determined.

FIG. 8 illustrates the results of the experiments. Conductivity of asolution of reactants and products is higher than a solution ofreactants alone. Table 2 further illustrates the correlation betweenconductivity and performic acid concentration.

TABLE 2 Conductivity Data % Performic Acid Conductivity (μS/cm) 0 3580.9 2120 4.49 2421 5.02 2631 7.44 2675 8.525 2920

Example 4

The system according to an embodiment of the invention was assembled,including a downward flow of the oxidizing agent inlet. The system wasoperated with a 97% formic acid concentration inlet flow of 17.6 mL/minand a 35% hydrogen peroxide concentration inlet flow of 2.4 mL/min.Samples were collected at 2, 5, 10, and 15 minutes and tested accordingto the iodometric titration procedure according to Example 2 forperformic acid concentration and hydrogen peroxide concentration. Theseresults are shown in Table 3 and FIG. 11.

TABLE 3 Titration Data Elapsed Time (min) % Performic Acid % HydrogenPeroxide 2 8.28 1.75 5 8.84 1.06 10 7.30 0.33 15 9.02 0.50

The results shown in Table 3 and FIG. 11 indicate that the performicacid concentration had reached a stable concentration with a standarddeviation of 0.007 within the first 2 minutes of the reaction.

Example 5

The peroxyformic acid generator according to the embodiments depicted inthe figures having multiple inlets to provide formic acid blend (formicacid, catalyst and corrosion inhibitor) as well as hydrogen peroxide wasevaluated under field conditions at a scale-up volume. The generator wasused at a salt water disposal well.

Beneficially, the PFA generated exceeded expectations in lab analysis.Approximately 15% of PFA was generated at the site of dosing. Thesampling points were both at the top and bottom sampling ports fromlaboratory generation compared to in the field generation are shown inTable 4.

TABLE 4 PFA Generation Residence Formic % Hydrogen Time Temperature acidblend 35% peroxide % PFA Peroxide Location (feet) (F.) 90 10 8.2 0.17Lab 10 120 81 19 9.61 0.85 Lab 10 120 70 30 11.94 2.72 Lab 10 120 67 3311.78 2.98 Lab 10 120 75 25 15.5 1.4 Field 90 100-105 80 20 12.92 0.85Field 90 100-105 88 12 7.1 0.2 Field 90 100-105 85 15 10.85 0 Field 90100-105

The increase in PFA generation is attributed to the modification of thehigh ambient temperatures coupled with the long residual time of theformic/peroxide mixture provided by the tubing from the point ofgeneration to the site of dosing (90 ft). Peroxide flow and formic acidflow were monitored via flow meters. Product formation was monitored viaconductivity as well as titration methods. Temperatures were monitoredusing probes in the generator. Flow of peroxide was challenged due toexcessive heat as well as the pumps ceasing because of air, which aresubject to modification through auto-priming valves as well as ventvalves that will remove air from the tubing allowing for bubble freeflow.

Example 6

The performance of the chemistry generated in the field according toExample 5 was evaluated for micro efficacy. PFA dosed at 250 ppm (˜25ppm active) indicates at least reduction in microbial numbers equivalentto 2-3 logs, as shown in FIG. 13. In the figures the GB refers to siteof treatment (gun barrel) measurement, whereas SWD refers to thedisposal water measurement for micro efficacy.

The percentage reduction of microbial numbers compared to incoming waterwas also evaluated. Microbial numbers were monitored using traditionalserial dilution bug bottles that select for SRB or APB populations. Allresults showed at least a 2-3 log reduction and in some case a 7 logreduction in microbial population.

The iron oxidation potential of PFA was further evaluated as PFA is anoxidant and is capable of oxidizing FeS into iron oxide. Samples drawnfrom the incoming water, site of treatment (gun barrel) and disposalwater (SWD) indicates a reduction in FeS concentration during treatment,as shown in FIG. 14. A consequence of this is an increased oilproduction.

Beneficially, disposal waters tested at the initial of PFA treatment andafter 15 days of treatment and a reduction of FeS was observed. FeS canbe oil wet and holds a lot of oil. Upon oxidation this oil is released.BS&W analysis provides a quantitative estimation on the amount of water,solids, emulsion and oil present in the samples. This analysis on thetwo samples indicates 97% oil which is 92% increase in the totalrecoverable oil before and after treatment with PFA.

The inventions being thus described, it will be obvious that the samemay be varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the inventions and all suchmodifications are intended to be included within the scope of thefollowing claims.

What is claimed:
 1. An adjustable biocide generator system for on-siteperformic acid forming composition generation comprising: an apparatuscomprising at least one inlet, a length of pipe, a heating device, andan outlet for dosing a performic acid forming composition from saidlength of pipe; wherein said inlet(s) are in fluid connection with saidlength of pipe and supply reagents to produce said performic acidforming composition in said length of pipe; wherein said reagentscomprise a formic acid source and an oxidizing agent; and wherein saidlength of pipe is in fluid connection with said outlet to dispense saidperformic acid forming composition.
 2. The system according to claim 1,wherein said performic acid forming composition is an individual ormixed performic acid forming composition according to a user-orsystem-inputted selection, and wherein the mixed performic acid formingcomposition comprises performic acid and an additional C1-C22percarboxylic acid.
 3. The system according to claim 1, wherein theformic acid source is formic acid, and wherein said oxidizing agent is1-50% w/v hydrogen peroxide.
 4. The system according to claim 1, whereinthe reagents do not include a chelating agent, stabilizing agent and/orchemical catalyst.
 5. The system according to claim 1, wherein thereagents further comprise a corrosion inhibitor and/or an additionalbiocide selected from the group consisting of gluteraldehyde, THPS, aquaternary amine, and TTPC.
 6. The system according to claim 1, furthercomprising at least one measurement device, wherein said measurementdevice measure one or more reaction kinetics or system operations forsaid performic acid forming composition generation.
 7. The systemaccording to claim 6, wherein said measurement device is selected fromthe group consisting of conductivity, weight, flow, pH, pressure,temperature, titrator for reagent concentration and combinationsthereof.
 8. The system according to claim 1, wherein said heating deviceis selected from the group consisting of a cartridge, heat exchanger,heat blanket, steam jacket, solar panels, steam preheat, an electricalsource and combinations thereof.
 9. The system according to claim 1,wherein said heating device maintains a temperature that does not exceed200° C. for the reagent temperature, and wherein said length of pipe isdesigned to accommodate at least 5 times the pressure of the system. 10.The system according to claim 1, further comprising a control softwarefor operating said apparatus to generate a user- or system-inputtedperformic acid forming composition and desired flow rate of saidperformic acid forming composition for on-site generation, wherein saidcontrol software determines the flow rate and/or timing of feeding ofsaid raw materials to said length of pipe and reaction time required forproduction of said user- or system-inputted performic acid formingcomposition and desired flow rate.
 11. The system according to claim 1,further comprising a data output means for sharing information relatedto said performic acid forming composition formulation, performic acidforming composition consumption or usage, additional performic acidforming composition production-related data or combinations of the same.12. The system according to claim 1, wherein the apparatus furthercomprises a safety release valve and/or rupture disk to vent the system,and wherein the apparatus comprises at least two inlets, wherein thefirst inlet doses a formic acid source to said length of pipe and thesecond inlet doses an oxidizing agent to said length of pipe, andoptionally wherein said second inlet does an oxidizing agent to saidlength of pipe via downward flow.
 13. A method of on-site generatingperformic acid forming composition comprising: providing a formic acidsource to a length of pipe at a desired flow rate; providing anoxidizing agent to said length of pipe at a desired flow rate;contacting said formic acid source with an effective amount of saidoxidizing agent within said length of pipe in the presence of a heatingdevice to form a performic acid composition; delivering said performicacid composition to a downstream process, wherein said performic acid isan individual or mixed performic acid composition according to a user-orsystem-inputted selection, wherein the reaction to form the performicacid composition begins generating yield instantaneously and reachesmaximum yield within 10 minutes or less.
 14. The method of claim 13,wherein the formic acid source is formic acid and the oxidizing agent ishydrogen peroxide, and wherein the hydrogen peroxide and the performicacid concentration generated on-site is from 2 wt-% to about 15 wt-% andhas a higher concentration to the unreacted hydrogen peroxide.
 15. Themethod of claim 13, wherein said heating device is selected from a groupconsisting of a cartridge, heat exchanger, heat blanket, steam jacket,solar panels, steam preheat, an electrical source and combinationsthereof, and wherein said heating device provides heat sufficient toraise the temperature of the solution within said pipe to a temperaturenot exceeding about 180° C.
 16. The method of claim 13, wherein saidheating device is a cartridge contained with said length of pipe andwherein the difference between said pipe's inner diameter and saidcartridge's diameter is less than about 5 inches.
 17. The method ofclaim 13, further comprising cooling said performic acid to atemperature at or below freezing to stabilize the performic acidcomposition.
 18. The method of claim 13, further comprising a step of:(a) measuring variables of the reaction to form the performic acidcomposition, wherein the measuring step measures conductivity,temperature, product levels, concentrations, IR/UV/VIS spectroscopy,pressure, performic acid and/or oxidant concentrations, and/or flowrate; and/or (b) controlling the method using control software foroperating said apparatus to generate a user- or system-inputtedperformic acid forming composition and said desired flow rate of saidperformic acid forming composition for on-site generation.
 19. Themethod according to claim 13, wherein the reaction reaches maximum yieldwithin 60 seconds or less, wherein the reaction generates at least about2% performic acid near instantaneously, the reaction generates at leastabout 4% performic acid within 1 minute, the reaction generates at leastabout 8% performic acid within 2 minutes, or the reaction generates atleast 15% performic acid within 30 minutes.
 20. A method of cleaningusing an on-site generated performic acid composition comprising:obtaining a user- or system-inputted performic acid composition on-siteusing the adjustable biocide generator system of claim 1; applying saidperformic acid composition in an amount sufficient to sanitize, bleachand/or disinfect a surface in need thereof.
 21. The method of claim 20,wherein the surface is a food item or a plant item and/or at least aportion of a medium, a container, an equipment, a membrane, a system ora facility for growing, holding, processing, packaging, storing,transporting, preparing, cooking or serving the food item or the plantitem.
 22. The method of claim 20, wherein the performic acid compositionis applied to the surface by means of a spray, immersion, foam, or gel.23. The method of claim 20, wherein the applying step lasts for at least5 seconds.
 24. The method of claim 20, wherein the performic acidcomposition reduces a microbial population by at least three log₁₀. 25.The method of claim 20, wherein the surface is liquid system, processwater, or surfaces of equipment that come in contact with liquidsystems.